they didn't ask for the tangent line, why did you find it?

the slope of the tangent line here is 4/3. thus the slope of the normal line is -3/4. now use the point-slope form:

y + 3 = (-3/4)(x - 4)

and solve for y

do the same thing for this point

equation of tangent line to B....-4/3x+25/3