Q 1 :

In ABC right angled at B, sinA=725, then the value of cos C is ............................

  • 725

     

  • 2425

     

  • 724

     

  • 247

     

(1)      725

 



Q 2 :

If 5 tan θ = 4, then the value of 5sinθ-3cosθ5sinθ+2cosθ is

  • 1/6

     

  • 1/7

     

  • 1/4

     

  • 1/5

     

(1)    1/6

 



Q 3 :

Given that sin α = 1/2 and cos β = 1/2, then the value of (β – α) is

  •  

  • 30°

     

  • 60°

     

  • 90°

     

(2)     30°

 



Q 4 :

If sinθ + cosθ = 2, then tanθ + cot θ =

  • 1

     

  • 2

     

  • 3

     

  • 4

     

(2)

sinθ+cosθ=2

Squaring on both sides, we get

sin2θ+cos2θ+2sinθcosθ=2

1+2sinθcosθ=2    [sin2θ+cos2θ=1]

2sinθcosθ=1 sinθcosθ=12

But tanθ+cotθ=sinθcosθ+cosθsinθ=sin2θ+cos2θcosθsinθ=2



Q 5 :

If 5 tanβ = 4, then 5sinβ-2cosβ5sinβ+2cosβ=

  • 1/3

     

  • 2/5

     

  • 3/5

     

  • 6

     

(1)

5tanβ=4  tanβ=45

 5sinβ-2cosβ5sinβ+2cosβ=5tanβ-25tanβ+2       [dividing cosβ by Nr. and Dr.]

                                    =5×45-25×45+2=26=13

 



Q 6 :

If x tan 60°cos 60°= sin60°cot 60°, then x =

  • cos30°

     

  • tan30°

     

  • sin30°

     

  • cot30°

     

(2)

xtan60°cos60°=sin60°cot60°

x×3×12=32×13x3=1

x=13x=tan30°   [tan30°=13]

 



Q 7 :

If sec θ – tan θ = m, then the value of sec θ + tan θ is :

  • 1-1m

     

  • m2-1

     

  • 1m

     

  • -m

     

(3)

Given, secθ-tanθ=m  ...(i)

We know that, sec2θ-tan2θ=1

(secθ-tanθ)(secθ+tanθ)=1

m(secθ+tanθ)=1

secθ+tanθ=1m

 



Q 8 :

If cos (α+β) = 0, then value of cos (α+β2) is equal to:

  • 12

     

  • 12

     

  • 0

     

  • 2

     

(1)

cos(α+β)=0=cos90°(α+β)=90°α+β2=45°

cos(α+β2)=cos45°=12

 



Q 9 :

The value of (sin2θ+11+tan2θ) is:

  • 0

     

  • 2

     

  • 1

     

  • – 1

     

(3)     1

 



Q 10 :

If tan2θ+cot2α=2, where θ=45° and θ°α90°, then the value of a is :

  • 30°

     

  • 45°

     

  • 60°

     

  • 90°

     

(2)       45°

 



Q 11 :

If sinθ=cosθ, (0°<θ<90°), then value of (secθ.sinθ) is:

  • 1/2

     

  • 2

     

  • 1

     

  • 0

     

(3)

sinθ=cosθtanθ=1=45°θ=45°

Now, secθ.sinθ=sec45°.sin45°=2×12=1



Q 12 :

If 5 tan θ-12=0, then the value of sin θ is

  • 512

     

  • 1213

     

  • 513

     

  • 125

     

(2)

Given,5tanθ-12=0tanθ=125=pbLet p=12k, b=5kh=p2+b2=(12k)2+(5k)2=144k2+25k2=169k2=13ksinθ=ph=12k13k=1213

 



Q 13 :

In ABC, right angled at B sinA=725, then the value of cos C is

  • 725

     

  • 2425

     

  • 724

     

  • 247

     

(1)

sinA=ph=BCAC=725cosC=bh=BCAC=725



Q 14 :

In the given figure, D is the mid-point of BC , then the value of cotycotx is

  • 2

     

  • 1/2

     

  • 1/3

     

  • 1/4

     

(2)

From the given figurecotycotx=ACBC÷ACCD=ACBC×CDAC=CDBC=CD2CD=12(Using cotθ=bp)

 



Q 15 :

If a tanθ=b the value of bsinθ-acosθbsinθ+acosθ is

  • b-ab2+a2

     

  • b+ab2+a2

     

  • b2+a2b2-a2

     

  • b2-a2b2+a2

     

(4)

We have, tanθ=baGiven expression is bsinθ-acosθbsinθ+acosθTaking cosθ common from the expression,it gives btanθ-abtanθ+a(i)Substituting tanθ=bainequation (i) givesb2a-ab2a+a=b2-a2b2+a2

 



Q 16 :

Which of the following trigonometric ratios are correctly written in context of ABC as given?

(i)sinA=BCAC(ii)tanC=BCAB(iii)cosC=ABAC(iv)secA=ACAB

  • (i) and (ii)

     

  • (ii) and (iv)
     

  • (i) and (iv)
     

  • (ii) and (iii)

     

(3)

WhenA is under considerationBase = AB, Perpendicular = BC, Hypotenuse = ACsinA=PerpendicularHypotenuse=BCACand secA=HypotenuseBase=ACABWhenC is underconsideration:Base = BC, Perpendicular = AB, Hypotenuse = ACtanC=PerpendicularBase=ABBCand cosC=BaseHypotenuse=BCAC

 



Q 17 :

If sinα=32,cosβ=32, then tanα·tanβ is:

  • 3

     

  • 13

     

  • 1

     

  • 0

     

(3)

Given 

sinα=32=sin60°α=60°And, cosβ=32=cos30°β=30°tanα·tanβ=tan60°·tan30°=3×13=1

 



Q 18 :

The value of θ for which 2sin 2θ=12,0°θ90° is

  • 30°

     

  • 60°

     

  • 45°

     

  • 90°

     

(2)

2sin 2θ=12sin 2θ=14sinθ=12=sin30°θ=30°

 



Q 19 :

58sec 260°-tan 260°+cos 245° is equal to

  • -53

     

  • -12

     

  • 0

     

  • 14

     

(3)

We have,

58sec 260°-tan 260°+cos 245°=58×(2)2-(3)2+122=58×4-3+12=52-3+12=5-6+12=0



Q 20 :

2tan30°1+tan 230° is equal to

  • sin60°

     

  • cos60°

     

  • tan60°

     

  • sin30°

     

(1)

We have, 

2tan30°1+tan 230°=2×131+132=231+13=2343=23×34=32=sin60°

 



Q 21 :

If cotθ=13,the value of sec 2θ+cosec 2θ is

  • 1

     

  • 40/9

     

  • 38/9

     

  • 513

     

(4)

Given, 

cotθ=13=cot60°θ=60°Now,sec 2θ+cosec 2θ=sec 260°+cosec 260°=(2)2+232=4+43=12+43=163=513

 



Q 22 :

Given that secθ=2, the value of1+tanθsinθ is

  • 22

     

  • 2

     

  • 32

     

  • 2

     

(1)

Given, 

secθ=2θ=45°Now,1+tanθsinθ=1+tan45°sin45°=1+112=212=22



Q 23 :

If x tan60°cos60°=sin60°cot60°,then x=

  • cos30°

     

  • tan30°

     

  • sin30°

     

  • cot30°

     

(2)

Given expression is 

x tan60°cos60°=sin60°cot60°x×3×12=32×13x×32=12x=13=tan30°



Q 24 :

If ΔABC is right angled at C, then the value of secA+Bis

  • 0

     

  • 1

     

  • 23

     

  • not defined

     

(4)

In ΔABC, C=90°givenAnd, A+B+C=180°A+B=90°or A+B=90°secA+B=sec90°=not defined

 



Q 25 :

If If tanα+cotα=2,then tan 20α+cot 20 α is equal to

  • 0

     

  • 2

     

  • 20

     

  • 220

     

(2)

We have,

tanα+cotα=2tanα+1tanα=2tan 2α-2 tanα+1=0(tanα-1)2=0tanα=1α=45°So,tanα=cotα=1Now,tan 20α+cot 20α=120+120=1+1=2

 



Q 26 :

The value of which of the following is definitely zero?

(i) sin 45°-cos45°(ii) tan 90°-cot90°(iii) sin 60°-cos30°(iv) tan30°-cot30°

  • both (i) and (iv)

     

  • both (i) and (iii)
     

  • only (i)

     

  • only (iii)

     

(2)

(i) sin45°=12,cos45°=12sin45°-cos45°=12-12=0(ii) tan90°=,cot90°=0tan90°-cot90°=not defined(iii) sin60°=32,cos30°=32sin60°-cos30°=32-32=0(iv)tan30°=13,cot30°=3tan30°-cot30°=13-3=1-33=-230

Hence, (i) and (iii) will definitely give zero.

 



Q 27 :

P and Q are acute angles such that P > Q. Then which of the following is definitely true?

(i) sinP<sinQ(ii) tanP>tanQ(iii) cosP>cosQ (iv) cosP>sinQ

  • only (i)

     

  • only (ii)

     

  • (i) and (ii) both

     

  • only (iv)

     

(2)

Given that P and Q are acute angles such that P > Q

Let P=60° Q=30°.Checking (i):We know that sinθ increases as θ increases  from  0° to 90°sin60°=32,sin30°=12sinQ<sinPThus (i) is not trueChecking (ii):We know that tanθincreases as θ increases  from  0° to 90°tanP>tanQHence (ii) is true.Checking (iii):We know that cosθ increases as θ increases  from  0° to 90°So (iii) is not true.Checking (iv):cosP=cos60°=12,sinQ=sin30°=12cosP=sinQ