To find such critical points, you have to differentiate the function and let the derivative equal zero. Since this function is y written in terms of x, but implicitly, you must use implicit differentiation. Do you know how to do that?
Answer:
70
Step-by-step explanation:
we have the angle of vertex in the isosceles triangle = 180-2*bottom coner= 180-65/2=50
3 angles in the equilateral triangle are equal to 60
we have 50 + 60 +h =the angle of PQR =180
h=70