જવાબ : cos 60o cos 30o − sin 60o sin 30o
=( 1/2 × √3/2 - √3/2 × ½ ) = (√3/4 - √3/4)=0
જવાબ : sin30°cos45°+cot45°sec60°-sin60°tan45°+cos30°sin90°
=(1/2)(1/√2)+1/2-(√3/2)1+(√3/2)1
=√2/2 + ½ - √3/2 + √3/2
=√2+1/2
જવાબ : sin 60o cos 30o + cos 60o sin 30o
=(√3/2 × √3/2 + ½ × ½ ) = (3/4 +1/4 )=4/4=1
જવાબ : cos 45o cos 30o + sin 45o sin 30o = ?
= (1/√2 × √3/2 + 1/√2 × ½ ) = (√3/2√2 + 1/2√2) = (√3 +1/2√2)
જવાબ : 5cos260°+4sec230°-tan245°sin230°+cos230°= 5(1/2)2 + 4(2√3)2 -(1)2(1/2)2+(√3/2)2 =(5/4+4×4/3-1)(1/4+3/4) =(5/4+16/3-1)(4/4) =[(15+64-12)/12](4/4) =(67/12)(1) =67/12
જવાબ : 2 cos2 60o + 3 sin2 45o − 3 sin2 30o + 2 cos2 90o
=2×(1/2)2+3×(1/√2)2-3×(1/2)2 + 2×(0)2
=2×1/4 + 3×1/2- 3×1/4+0
=(1/2+3/2-3/4)
=[(2+6-3)/4]
=54
જવાબ : cot2 30o − 2 cos2 30o – 3/4sec2 45o + 1/4cosec230o
= (√3)2-2×(√3/2)2-3/4×(√2)2+1/4×(2)2
= 3-2×3/4-3/4×2+1/4×4
= 3-3/2-3/2+1
= 4-(3/2+3/2)
= 4-3= 1
જવાબ : (sin2 30o + 4 cot2 45o − sec2 60o )(cosec2 45o sec2 30o)
=[(1/2)2+4×(1)2-(2)2] [(√2)2 (2/√3)2]=(1/4+4-4) (2×4/3)
=1/4×8/3=2/3
જવાબ : 4cot230° +1sin230° -2 cos245o -sin20o =4(√3)2+1(1/2)2 - 2×(1/√2)2-(0)2 =4/3+1/4-2×1/2-0 =4/3+4-1 =4/3+3 =(4+9)/3 = 13/3
જવાબ : LHS=1-sin 60ocos 60o=1-√3212=(2-√32)12=(2-√32)×2=2-√3RHS= tan 60o-1tan 60o+1=√3-1√3+1=√3-1√3+1×√3 -1√3 -1=(√3-1)2(√3)2-12=3+1-2√33-1=4-2√32=2-√3
Hence, LHS = RHS
∴ 1-sin 60ocos 60o=tan 60o-1tan 60o+1
જવાબ : LHS = (cos 30° + sin 60°)/(1 + sin 30° + cos 60°)
= = √32
Also, RHS = cos 30° =√3/2
Hence, LHS = RHS
∴ (cos30° + sin60°)/(1+sin30°+cos60°) = cos30°
જવાબ : sin 60o cos 30o − cos 60o sin 30o
=(3√2)×(3√2)−(1/2)×(1/2)
=3/4−1/4
=2/4
=1/2
Also, sin 30o =1/2
જવાબ : cos 60o cos 30o + sin 60o sin 30o
=(1/2)×( √3/2)+(√3/2)×(1/2)
=√3/4+√3/4
=√3/2
Also, cos 30o =√3/2
∴ cos 60o cos 30o + sin 60o sin 30o = cos 30o
જવાબ : 2 sin 30o cos 30o
=2×1/2×3√2 = 3√2
Also, sin 60o = 3√2
∴ 2 sin 30o cos 30o = sin 60o
જવાબ : 2 sin 45o cos 45o
=2×1/√2×1/√2 =1
Also, sin 90o = 1
∴ 2 sin 45o cos 45o = sin 90o
જવાબ : tan 2A = tan 60o = √3
= = = = √3
∴ tan2A =
જવાબ : A = 30o
⇒ 2A = 2 × 30o = 60o
cos 2A = cos 60o = 1212
= = = = = ½
∴ cos 2A=
જવાબ : A = 30o
⇒ 2A = 2 × 30o = 60o
sin 2A = sin 60o = √3/2
= = = = =
∴ sin 2A=2tan A1+tan2Asin 2A=2tan A1+tan2A
જવાબ : A = 45o
⇒ 2A = 2 × 45o = 90o
cos 2A = cos 90o = 0
2 cos2 A − 1 = 2 cos2 45o − 1 = 2×(1/√2)2 − 1 = 2×1/2 −1 = 1−1 = 0
Now, 1 − 2 sin2 A = 1−2×(1/√2)2 = 1 − 2×1/2 =1 − 1 = 0
∴ cos 2A = 2 cos2 A − 1 = 1 − 2 sin2 A
જવાબ : A = 45o
⇒ 2A = 2 × 45o = 90o
sin 2A = sin 90o = 1
2 sin A cos A = 2 sin 45o cos 45o = 2×1/√2×1/√2 = 2×1/2 = 1
∴ sin 2A = 2 sin A cos A
જવાબ : LHS = tan2θ/(1+tan2θ) + cot2θ/(1+cot2θ) =tan2θ/sec2θ + cot2θ/cosec2θ (∵sec2θ−tan2θ=1 and cosec2θ−cot2θ=1) =sin2θcos2θ1cos2θ + cos2θsin2θ1sin2θ =sin2θ+cos2θ =1 =RHS
Hence, LHS = RHS
જવાબ : LHS= (1+tan2θ)cotθ/cosec2θ =sec2θcotθ/cosec2θ = 1cos2θ × cosθsinθ1sin2θ = sin2θ/cosθsinθ =sinθ/cosθ =tanθ
Hence, L.H.S. = R.H.S.
જવાબ : LHS=1+ tan2θ/(1+secθ) =1+ (sec2θ−1)/(secθ+1) =1+ (secθ+1)/(secθ−1)(secθ+1) =1+(secθ−1) =secθ =RHS
જવાબ : LHS=1+cot2θ(1+cosecθ) =1+(cosec2θ−1)(cosecθ+1) (∵cosec2θ-cot2θ=1) =1+ (cosecθ+1)(cosecθ−1)/(cosecθ+1) =1+(cosecθ−1) =cosecθ =RHS
જવાબ : LHS =secθ(1−sinθ)(secθ+tanθ) =(secθ−secθsinθ)(secθ+tanθ) =(secθ−1cosθ×sinθ)(secθ+tanθ) =(secθ−tanθ)(secθ+tanθ) =sec2θ−tan2θ =1 =RHS
જવાબ : LHS=1/(1+sinθ)+1/(1-sinθ) = [(1-sinθ)+(1+sinθ)]/(1+sinθ)(1-sinθ) = 2/(1-sin2θ)= 2/cos2θ = 2sec2θ=RHS
જવાબ : LHS= cos2θ+1/(1+cot2θ) = cos2θ +1/cosec2θ =cos2θ+sin2θ=1= RHS
જવાબ : LHS =tan2θ – 1/cos2θ = sin2θ/cos2θ – 1/cos2θ = sin2θ-1/cos2θ= -cos2θ/cos2θ = -1= RHS
જવાબ : LHS=cot2θ -1sinθ =cos2θsin2θ- 1/sin2θ =cos+θ- 1/sin2θ =-sin2θ/sin2θ= -1 =RHS
જવાબ : LHS= cosecθ(1+cosθ)(cosecθ – cotθ ) = (cosecθ + cosecθ × cosθ )( cosecθ – cotθ ) = (cosecθ + cosθ sinθ)(cosecθ−cotθ) = (cosecθ+cotθ)(cosecθ−cotθ) = cosec2θ−cot2θ (∵cosec2θ−cot2θ=1) =1 =RHS
જવાબ : LHS=(1+cosθ)(1−cosθ)(1+cot2θ) =(1−cos2θ)cosec2θ =sin2θ×cosec2θ =sin2θ × 1/sin2θ =1 =RHS
જવાબ : LHS=1/(1+tan2θ)+1/(1+cot2θ) =1/sec2θ + 1/cosec2θ = cos2θ+sin2θ =1 =RHS
જવાબ : LHS= sin2θ + 1/(1+tan2θ) =sin2θ+1/sec2θ (∵sec2θ−tan2θ=1) =sin2θ+cos2θ =1 =RHS
જવાબ : LHS=(1−cos2θ)sec2θ =sin2θ×sec2θ (∵sin2θ+cos2θ=1) =sin2θ× 1/cos2θ = sin2θ/cos2θ =tan2θ =RHS
જવાબ : LHS= (sec2θ−1)(cosec2θ−1) =tan2θ ×cot2θ (∵sec2θ−tan2θ=1 and cosec2θ−cot2θ=1) =tan2θ × 1/tan+θ =1 = RHS
જવાબ : LHS= (sec2θ−1)cot2θ = tan2θ×cot2θ (∵sec2θ−tan2θ=1) =1/cot2θ × cot2θ =1 =RHS
જવાબ : LHS= (1+cot2θ)sin2θ =cosec2θ sin2θ (∵cosec2θ−cot2θ=1) =1/sin2θ × sin2θ =1 Hence, LHS=RHS
જવાબ : LHS=(1−cos2θ)cosec2θ =sin2θ cosec2θ (∵cos2θ+sin2θ=1) =1/cosec2θ × cosec2θ =1 Hence, LHS = RHS
જવાબ : LHS = (sin65°+cos25°)(sin65°−cos25°) = sin265°−cos225° = sin2(90°−25°) −cos225° =cos225°−cos225° =0 =RHS
જવાબ : LHS = cos257°−sin233° =cos2(90°−33°) −sin233° = sin233°−sin233° =0 =RHS
જવાબ : LHS=sin248° + sin242° =sin2(90°−42°) +sin242° =cos2420 + sin242° =1 =RHS
જવાબ : LHS = tan266° − cot224° =tan2(90°−24°) − cot224° =cot224°− cot224° = 0 =RHS
જવાબ : LHS = cos275° + cos215° =cos2(90°−15°) + cos215° =sin215°+cos215° =1 =RHS
જવાબ : LHS = cosec272° −tan218° =cosec2(90°−18°) −tan218° =sec218° − tan218° =1 =RHS
જવાબ : LHS = cosec80°−sec10° =cosec(90°−10°) −sec10° =sec10°−sec10° = 0 = RHS
જવાબ : LHS = tan71°−cot19° = tan(90°−19°) − cot19°= cot19°−cot19° =0 = RHS
જવાબ : LHS= cos81° − sin9° =cos(90°−9°) −sin9° = sin9°−sin9° = 0 =RHS
જવાબ : cot38°/tan52° =cot(90°−52°)/tan52° =tan52°/tan52° =1 [∵tan (90−θ) = cot θ]
જવાબ : cosec42°/sec48° =cosec(90°−48°)/sec48° =sec48°/sec48° =1 [∵sec (90−θ) = cosec θ]
જવાબ : cos35°/sin55° = cos(90°−55°)/sin55° = sin55°/sin55° =1 [∵sin (90−θ) = cosθ]
જવાબ : tan27°/cot63° =tan(90°−63°)/cot63°=cot63°cot63° =1 [∵tan (90−θ) = cot θ]
જવાબ : We have, sinθ=cos(θ-45°)
⇒cos(90°-θ)=cos(θ-45°) Comparing both sides, we get 90°- θ = θ - 45° ⇒θ+θ = 90°+45° ⇒2θ=135° ⇒θ=(135/2)° ∴ θ=67.5°જવાબ : (sinA+cosA)secA=(sinA+cosA)/cosA=sinA/cosA+cosA/cosA=tanA+1= 5/12+1/1 =(5+12)/12 = 17/12
જવાબ : cos1° cos2° ... cos180°=cos1° cos2° ... cos90° ... cos180°=cos1° cos2° ... 0 ... cos180°=0
જવાબ : sin50°/cos40° + cosec40°/sec50° -4cos50° cosec40° = cos(90°-50°)/cos40° + sec(90°-40°)/sec50° - 4sin(90°-50°) cosec40°
=cos40°/cos40° + sec50°/sec50° - 4sin40°/sin40° = 1+1 – 4 = -2જવાબ : sin48° sec42°+cos48° cosec42°= sin48° cosec(90°-42°) + cos48° sec(90°-42°) =sin48° cosec48°+cos48° sec48° =sin48°/sin48° + cos48°/cos48° =1+1 = 2
જવાબ : We have,
sec2A = cosec(A−42°)
જવાબ : sin3A=cos(A−26°)
⇒cos(90°−3A)=cos(A−26°) [∵sinθ=cos(90°−θ)] ⇒90°−3A=A−26° ⇒116°=4A ⇒A=116°/4 = 290જવાબ : tan2A=cot(A−12°)
=>cot(90°−2A)=cot(A−12°) [∵tanθ=cot(90°−θ)] =>(90°−2A)=(A−12°) =>102°=3A =>A=102°/3=34°જવાબ : sec4A=cosec(A−15°)
=> cosec(90°−4A)=cosec(A−15°) [∵secθ=cosec(90°−θ)] =>90°−4A=A−15° =>105°=5A =>A=105°/5 = 21°જવાબ : tan13° tan37° tan45° tan53° tan77°
= tan13° tan37° cot(90° - 53°) cot(90° -77°) 1 = tan13° tan37° cot37° cot13° 1 = - 5/3 =2/3 – 5/3 =−1જવાબ : AB/AC = cos 30°
⇒AB/20 = √3/2 ⇒AB = (20×√3/2 ) = 10√3cmજવાબ : From the given right-angled triangle, we have:
BC/AC = sin 30°
જવાબ : From right-angled ∆ABC, we have:
AB/AC=cos 45° ⇒AB/3√2 =1/√2 ⇒ AB=3 cmજવાબ : From right-angled ∆ABC, we have:
BC/AC = sin 45°
જવાબ : cos(A−B)=cosA cosB+sinA sinB
⇒cos(45°−30°)=cos45°cos30°+sin45°sin30° ⇒cos(15°) = + ⇒cos15°= ∴ cos15°=જવાબ : Let A=45° and B=30°Let A=45° and B=30°
sin(A+B)=sinA cosB+cosA sinB
જવાબ : 3(x2−1/x2) = = = = = 1/3
જવાબ : Here, tan (A − B) = 1/√3
⇒ tan (A − B) = tan 30o [∵ tan 30o = 1/√3 ]
⇒ A − B = 30o ...(A)
Also, tan (A + B) = √3
⇒ tan (A + B) = tan 60o [∵ tan 60o = √3]
⇒ A + B = 60o ...(B)
Solving (A) and (B), we get:
A = 45o and B = 15o
જવાબ : Here, sin (A − B) = 1212
⇒ sin (A − B) = sin 30o [∵ sin 30o = 1212]
⇒ A − B = 30o ...(A)
Also, cos (A + B) = 1212
⇒ cos (A + B) = cos 60o [∵ cos 60o = 1212]
⇒ A + B = 60o ...(B)
Solving (A) and (B), we get:
A = 45o and B = 15o
જવાબ : Here, sin (A + B) = 1
⇒ sin (A+ B) = sin 90o [∵ sin 90o = 1]
⇒ A + B = 90o ...(A)
Also, cos (A − B) = 1
⇒ cos (A − B) = cos 0o [∵ cos 0o = 1]
⇒ A − B = 0o ...(B)
Solving (A) and (B), we get:
A = 45o and B = 45o
જવાબ :
1-B, 2-A, 3-C
જવાબ :
1-B, 2-C, 3-A
1 |
Sin 0° |
A |
32 |
2 |
Sin 30° |
B |
0 |
3 |
Sin 45° |
C |
½ |
4 |
Sin 60° |
D |
1/√2 |
જવાબ :
1-B, 2-C, 3-D, 4-A
1 |
Sin θ |
A |
Perpendicular ÷ Base |
2 |
Cos θ |
B |
Perpendicular ÷ Hypotenuse |
3 |
Tan θ |
C |
Base ÷ Hypotenuse |
જવાબ :
1-B, 2-C, 3-A
1 |
Cos 0° |
A |
½ |
2 |
Cos 30° |
B |
1/√2 |
3 |
Cos 45° |
C |
32. |
4 |
Cos 60° |
D |
1 |
જવાબ :
1-D, 2-C, 3-B, 4-A
1 |
Cot 60° |
A |
2 |
2 |
Sec 60° |
B |
2/ |
3 |
Cosec 60° |
C |
1/. |
જવાબ :
1-C, 2-A, 3-B
1 |
Cot 30° |
A |
2/ |
2 |
Cosec 30° |
B |
3 |
3 |
Sec 30° |
C |
2 |
જવાબ :
1-B, 2-C, 3-A
1 |
Sin 90° |
A |
NA. |
2 |
Cos 90° |
B |
1 |
3 |
Tan 90° |
C |
0 |
જવાબ :
1-B, 2-C, 3-A
1 |
Cot θ |
A |
Hypotenuse ÷ Base |
2 |
Cosec θ |
B |
Base ÷ Perpendicular |
3 |
Sec θ |
C |
Hypotenuse ÷ Perpendicular |
જવાબ :
1-B, 2-C, 3-A
1 |
Tan 0° |
A |
1 |
2 |
Tan 30° |
B |
. |
3 |
Tan 45° |
C |
1/ |
4 |
Tan 60° |
D |
0 |
જવાબ :
1-D, 2-C, 3-A, 4-B
Math
Chapter 08 : Introduction to Trigonometry
The GSEB Books for class 10 are designed as per the syllabus followed Gujarat Secondary and Higher Secondary Education Board provides key detailed, and a through solutions to all the questions relating to the GSEB textbooks.
The purpose is to provide help to the students with their homework, preparing for the examinations and personal learning. These books are very helpful for the preparation of examination.
For more details about the GSEB books for Class 10, you can access the PDF which is as in the above given links for the same.