Question

A student solved the equation sin2x/cosx=2, 0<=x<=pi and found the answer of pi/2 describe the students error

Answer 1

For the given equation ⇒⇒⇒ $\frac{sin \ 2x}{cos \ x} =2$
and the given range 0 ≤ x ≤ π
We should note that the zeros of the denominator will be at 
cos x = 0
∴ $x = cos^{-1} 0 = \frac{\pi}{2}$
So, the given equation is undefined at π/2
So, the students error is the division by zero.


See the attached figure which represents the graph of the given equation and we can see it is undefined at π/2