Question

Evaluate: sin theta cos (90-theta)+cos theta sin (90-theta)

Answer 1

cosA,sin(90-A)+sin A,cos(90-A)
Cos A .Cos A + Sin A. Sin A
=Cos^2 A + Sin^2 A
=1
sol=1
Hope it helps...

Answer 2

Answer:

$Value \: of \: \\</p><p>sin\theta cos(90-\theta)+cos\theta sin(90-\theta)\\=1$

Step-by-step explanation:

$Value \: of \: \\</p><p>sin\theta cos(90-\theta)+cos\theta sin(90-\theta)$

=$sin\theta \times sin\theta + cos\theta \times cos\theta$

= $sin^{2}\theta + cos^{2}\theta$

/* We know the Trigonometric identity:

$\boxed {sin^{2}\theta+cos^{2}\theta = 1 }$*/

= $1$

Therefore,

$Value \: of \: \\</p><p>sin\theta cos(90-\theta)+cos\theta sin(90-\theta)\\=1$