Prove that sin²∅+cos²∅=1 ?

Step-by-step explanation:

Let ABC be a right angled triangle where there's a right angle in B . Let the measure of the angle BAC be ∅. So,

Also,

Now adding the values of sin^2∅& cos^2∅,

But we know that

by applying Pythagorean Theorem

So ,

y - y1 = m(x- x1)

y - (-5) = 2/3(x -0)

y + 5 = 2/3x

y = 2/3x - 5