Question

A student solved the equation sin2x/cos x and found an answer of pi/2 Describe the student's error

Answer 1

To find:

To determine whether the x = pi/2 is the answer of the equation

`(\sin2x)/(\cos x)=2`

Solution:

The solution of the equation is as follows:

`\begin{gathered} (\sin2x)/(\cos x)=2 \\ (2\sin x\cos x)/(\cos x)=2 \\ \sin x=1 \\ x=(\pi)/(2) \end{gathered}`

But at x = pi/2, the denominator of the function is zero, so, the function is not defined at x = pi/2.

Thus, the answer is "The function is not defined at x = pi/2. So, it is not the answer to the equation."