Question

Step 4:
sin(x)
tan(x)
In which step did Melanie make the first error, and which expression should she have written in that step?
sin(x)
cos(x)
(cos(x))
step 1:
cos(x)
sin(x)
O step 1: (sin(x))
O step 4; cos(x)
O step 4; csc(x)