# What is sin x + cos x in terms of sine?

**Solution:**

To convert sin x + cos x into sine expression we will be making use of trigonometric identities.

Using pythagorean identity,

sin^{2}x + cos^{2}x = 1

So, cos^{2}x = 1 - sin^{2}x

By taking square root on both the sides,

cosx + sinx = sinx ± √1 - sin^{2}x

Using complement or cofunction identity,

cosx = sin(π/2 - x)

sinx + cosx = sinx + sin(π/2 - x)

Thus, the expression for sin x + cos x in terms of sine is sin x + sin (π/2 - x).

## What is sin x + cos x in terms of sine?

**Summary:**

The expression for sin x + cos x in terms of sine is sin x + sin (π/2 - x).

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