Question

If Sin θ = 3/5 the value of (1 − Cos2 θ) is
A)9/5 B)6/10 C)9/25 D)25/9
​

Answer 1

Given :- If Sin θ = 3/5 the value of (1 − Cos2 θ) is

A)9/5

B)6/10

C)9/25

D)25/9

Solution :-

→ sin θ = 3/5 = P/H

so,

→ B = √(H² - P²) { By pythagoras theorem. }

→ B = √(5² - 3²) = √(25 - 9) = √16 = 4

then,

→ cos θ = B/H = 4/5

therefore,

→ (1 - cos² θ)

→ 1 - (4/5)²

→ 1 - (16/25)

→ (9/25) (C) (Ans.)

Learn more :-

prove that cosA-sinA+1/cos A+sinA-1=cosecA+cotA

https://brainly.in/question/15100532

help me with this trig.

https://brainly.in/question/18213053

Answer 2

Given :  Sin θ = 3/5

To Find :   value of  1 - Cos²θ    or  1 - Cos2θ

A)9/5 B)6/10 C)9/25 D)25/9

Solution:

Sin² θ   +  Cos²θ = 1

=> Sin² θ  = 1 -  Cos²θ

Sin θ = 3/5

=> (3/5)² =  1 -  Cos²θ

=> 9/25 = 1 -  Cos²θ

Hence value of  1 -  Cos²θ   is 9/25

1 - Cos2θ

Cos2θ = Cos²θ  - Sin² θ

= 1 - ( Cos²θ  - Sin² θ)

= (  1 -  Cos²θ ) + Sin² θ

=  2 Sin² θ

=  2 ( 9/25)

= 18/25

but 18/25 is not in options

Hence correct Question is  value of  1 - Cos²θ   = 9/25

Learn More

Ifsin 990° sin 780° sin 390°+=K(tan 405° – tan 360°) then Kicos 540 ...

brainly.in/question/22239477

Maximum value of sin(cos(tanx)) is(1) sint (2)

brainly.in/question/11761816

evaluate cot[90-theta].sin[90-theta] / sin theta+cot 40/tan 50 - [cos ...

brainly.in/question/2769339