Thread: Finding the equation of trig function

A trig function has the form y= acos^(2)x + bcosx - 1.
If x equals pi/3, pi, 5pi/3, find the values of a and b and show all calculations.

Ok, my equation is like this

y=cos^2x+0.5cosx-0.5

Is it right? Could someone just verify if I have it right or wrong and why? thanks

we need more information than what you're giving us. If you just give us the x-values, then y is variable, which means a and b vary as well