Question

find the equation for this trig function from those given points. (this is the derivative of y=-sin(x))

x slope of tangent
0 ---> -1
pi/4 ---> -0.71224
pi/2 ---> -0.03870
3pi/4 ---> 0.74527
pi ---> 0.99971
5pi/4 ---> 0.71224
3pi/2 ---> 0.03870
7pi/4 ---> -0.74527
2pi ---> -0.99971

Please help!