Solve Wave Superposition: 2Asin(7π(x+vt)) cos (3π(x+vt)) at t=0

[kpou]

Homework Statement

Two waves are produced on a string with length of 1m. Wavelength of one is .5m Wavelength of the other is .2m. Amplitude and velocity are the same.
Show that 2Asin(7pi(x + vt)) cos(3pi(x + vt)).
At t=0 what locations are the max/min displacement at?

Homework Equations

The Attempt at a Solution

I can solve the first part no problem. We have Eq we needed to show. Then I take z'(x) and have 2pi*A(2cos(4pi*x)+5cos(10pi*x)) and = 0 to get crit points.. This is where I am stuck. My calculator is unable to compute the graph at such small y apparently. I was unfortunately unable to find anything on the internet on how to solve this. Any help would be greatly appreciated.

 

[kpou]

So you I fixed my calculator, problem solved ><