y=10cos(2π/3)(x-.3)+50

x=17.2

i plugged this into the calculator and i got -34.5, but the answer is 43.3 how do i get that answer?

4 answers

I got 43.3 on mine

show your steps so I can find your error.
btw, did you switch to radians ?
i typed in exactly that equation into the calculator 10cos(2π/3)(17.2-.3)+50
and yes my calculator is in radian mode
here is my sequence of button-pushings:

17.2
-
.3
= ----> 16.9
x
2
x
π
÷
3
= ---> 35.3952...
cos
= ----> -.66913...
x
10
+
50
= -----> 43.308...
thank you so much!