Establish the following identity:
sin^2(-theta)+cos^2(-theta)=1
i understand sin^2(theta)+cos^2(theta)=1 and cos(-theta)=cos(theta) and sin(-theta)=-sin(theta) so how do i approach the identity above.

Question

Establish the following identity:
sin^2(-theta)+cos^2(-theta)=1
i understand sin^2(theta)+cos^2(theta)=1 and cos(-theta)=cos(theta) and sin(-theta)=-sin(theta) so how do i approach the identity above.

binary3i · Answer

see you have sin(-theta) = - sin(theta)
and cos(-theta) = cos (theta)
just substitute it into
cos^2(-theta) + sin^2(-theta)=1
it will be
cos^2(theta)+(-1)^2sin^2(theat)=1
cos^2(theta) + sin^2(theta)=1

shamim · Answer

no

binary3i · Answer

what no

shamim · Answer

$$\sin ^{2}(- \theta)=(-\sin \theta)^{2}=\sin ^{2} \theta$$

shamim · Answer

did u get it

binary3i · Answer

did you saw what i have written above. see properly.

anonymous · Answer

ohh okay what shamim put about sin^2(-theta) =sin^2(theta) just made my life a whole lot better thx lol. and u too binary