# How do you draw the graph of y=-cosx for 0<=x<2pi?

Jan 2, 2018

#### Explanation:

I am first assuming you understand the graph of $y = \cos x$ pretty well:

color(blue)(y = cosx

graph{cosx [-0.4, 6.5, -2.5, 2.5]}

Now we must use our knowledge of tranformation, if $y = f \left(x\right)$ then $y = - f \left(x\right)$ represents $y = f \left(x\right)$ reflected in the $y$ axis, or in other words turning any posotive values of $y$, into negative, etc...

So hence just flip horozontally:

 color(green)(y = -cosx  graph{-cosx [-0.4, 6.5, -2.5, 2.5]}