SOLUTION: q(x)=5.3cos(pi(x)/9) what is the period? I know the amplitude is 5.3 but I can't find the period.

Algebra ->  Trigonometry-basics -> SOLUTION: q(x)=5.3cos(pi(x)/9) what is the period? I know the amplitude is 5.3 but I can't find the period.      Log On


   

Question 901688: q(x)=5.3cos(pi(x)/9)
what is the period?
I know the amplitude is 5.3 but I can't find the period.
Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
The standard trig form for cos is
y = Acos(Bx+C) + D
we are given
q(x)=5.3cos(pi(x)/9)
note that C and D are both 0 and pi = 180 degrees, therefore
q(x) = 5.3cos(20x)
the period(T) for sin and cos = (2*pi) / B
B = 20 and pi = 180
T = (2 * 180) / 20 = 18