max/min with trig funtions problem
1. The problem statement, all variables and given/known data
Within the interval ( -22.27, 40.55 ), for what value of x does f(x) take on a minimum if
Later the question asks for the maximum as well.
2. The attempt at a solution
I know to find the critical values to take the first derivative and set it equal to zero, then solve for x. When I do that I get the equation...
When I solve this guy, by manipulating the equation to get tan(.1x)=-.47/.61, I get only one value, x=-6.56487, which is the minimum value. But I also need a maximum value. I've tried both end points within the interval and they were wrong. Is there something I'm missing here?
Any help would be appreciated.