If theta is an acute angle and sin theta = cos theta , then value of 2 tan^2 theta + sin^2 theta - 1 !! Plz fast Only 1 day to go for my Maths SA1 :(((
Answers
Answered by
2
2tan²theta+sin²theta-1
2sin²theta/cos²theta+sinu²theta-sin²theta-cos²theta
2sin²theta/cos²theta-cos²theta
2(1-cos²theta)-cos²theta(1-cos²theta)/cos²theta
(2-cos²theta)(1-cos²theta)/cos²theta
Since sin theta=cos theta
(2-cos²theta)(1-siñ²theta)/1-sin²theta
=2-cos²theta
=2sin²theta-cos²theta.
Since cos theta=sin theta
It equals to sin²theta or cos²theta
Here theta equals 45° ( see Ria's solution) So the value is 1/2.
2sin²theta/cos²theta+sinu²theta-sin²theta-cos²theta
2sin²theta/cos²theta-cos²theta
2(1-cos²theta)-cos²theta(1-cos²theta)/cos²theta
(2-cos²theta)(1-cos²theta)/cos²theta
Since sin theta=cos theta
(2-cos²theta)(1-siñ²theta)/1-sin²theta
=2-cos²theta
=2sin²theta-cos²theta.
Since cos theta=sin theta
It equals to sin²theta or cos²theta
Here theta equals 45° ( see Ria's solution) So the value is 1/2.
ria113:
can you please explain me second line of your answer
tanx=sinx/cosx and sin²x+cos²x=1
Answered by
0
if there is any mistakes in my answer please tell me in comment.
Attachments:
Similar questions