Math Ch 8: Introduction to Trigonometry PYQs | CBSE Class 10

CBSE

1

If $\theta$ is an acute angle and $7+4\sin\theta=9$, then the value of $\theta$ is:

[1]

2

The value of $\tan^{2}\theta-(\frac{1}{\cos\theta}\times\sec\theta)$ is:

[1]

3

(a) If $x\cos 60^{\circ}+y\cos 0^{\circ}+\sin 30^{\circ}-\cot 45^{\circ}=5$, then find the value of $x+2y$.

OR

(b) Evaluate: $\frac{\tan^{2}60^{\circ}}{\sin^{2}60^{\circ}+\cos^{2}30^{\circ}}$

[2]

4

(a) Prove that: $\frac{\tan\theta}{1-\cot\theta}+\frac{\cot\theta}{1-\tan\theta}=1+\sec\theta\csc\theta$

OR

(b) Prove that: $\frac{\sin A+\cos A}{\sin A-\cos A}+\frac{\sin A-\cos A}{\sin A+\cos A}=\frac{2}{2\sin^{2}A-1}$

[3]

5

If $\sec~\theta-\tan~\theta=m$, then the value of $\sec~\theta+\tan~\theta$ is:

[1 mark]

6

If $\cos(\alpha+\beta)=0$, then value of $\cos(\frac{\alpha+\beta}{2})$ is equal to :

[1 mark]

7

Evaluate: $2\sqrt{2}\cos~45^{\circ}\sin~30^{\circ}+2\sqrt{3}\cos~30^{\circ}$

[2 marks]

8

If $A=60^{\circ}$ and $B=30^{\circ}$, verify that :
$\sin(A+B)=\sin~A~\cos~B+\cos~A~\sin~B$

[2 marks]

9

Prove that: $\frac{\tan~\theta}{1-\cot~\theta}+\frac{\cot~\theta}{1-\tan~\theta}=1+\sec~\theta~\csc~\theta$

[3 marks]

10

If \( 2 \tan A=3 \), then the value of \( \frac{4 \sin A+3 \cos A}{4 \sin A-3 \cos A} \) is

[1 mark]

11

\( \left[\frac{3}{4}\tan^{2}30^{\circ}-\sec^{2}45^{\circ}+\sin^{2}60^{\circ}\right] \) is equal to

[1 mark]

12

(a) If \( \sin \theta+\cos \theta=\sqrt{3} \), then find the value of \( \sin \theta \cdot \cos \theta \).

OR

(b) If \( \sin \alpha=\frac{1}{\sqrt{2}} \) and \( \cot \beta=\sqrt{3} \), then find the value of \( \operatorname{cosec} \alpha+\operatorname{cosec} \beta \).

[2 marks]

13

Prove that: \( \frac{\tan \theta+\sec \theta-1}{\tan \theta-\sec \theta+1}=\frac{1+\sin \theta}{\cos \theta} \)

[3 marks]