Question

please answer all of them I really don't know​

Answer 1

Step-by-step explanation:

1)1/(1+sin(theta))+1/(1-sin(theta))

=(1(1-sin(theta))+1(1+sin(theta)))/(1-sin(theta))(1+sin(theta))

=(1-sin theta +1 +sin theta)/(1-sin²theta)

=(1+1)/cos²theta

=2(1/cos²theta)

=2sec²theta

2)cos²theta(1+tan²theta)

=cos²theta(1+(sin²theta/cos²theta))

=cos²theta+sin²theta

=1

3) since sin ²theta =√(1+cos theta)(1-cos theta)

therefore 1-cos theta = sin²theta/1+cos theta

therefore on evaluating the question we get cos theta +1/sin theta

=cot theta + cosec theta

sry cant prove the 4th one

i am in 8th standard