Parallel lines have the same slope.
The derivative determines the slope, so .
So for what x does ?
Let f and g be the functions defined by f(x)=sinx and g(x)=cosx. for which of the following values of a is the tangent line to f at x=a parallel to the tangent line to g at x=a? The answer is 3pi/4 but I dont understand how to get to that...
How would I go about finding that answer? thanks
the solution of the equation tan(x) = -1 is not a single value but a set of numbers. There is a main interval where you can find the first solution:
. All other solutions are produced by adding multiples of . That means the next solution is:
I've attached a diagram of the functions f(x) = tan(x) and the line y = -1. The x-coordinate of the intersection points are the solutions of your equation.