Stage: 4 and 5 Challenge Level:
Can you prove an algebraic statement using geometric reasoning?
Slices of Pi
Stage: 5 Challenge Level:
How are $\sin x$, $\cos x$ and $\tan x$ related to each other? Can you make sense of the the 'slices'?
By considering a point on a unit circle, can you use geometry to find the derivatives of $\sin x$ and $\cos x$?
Can you work out the equation of the function from its graph?