Question

Explain why (cos((theta))? + (sin((theta))2 = 1

Answer 1

Imagine a right triangle where a and b are the legs and c is the hypothenuse.

Pitagora: a²+b²=c²

Divide by c

(a/c)²+(b/c)²=1

But a/c=sin(B) and b/c=cos(B)

Thus sin² + cos² = 1