Find the slope of the normal at the point ‘t’ on the curve

If the tangent to a curve at a point (x, y) is equally inclined to the coordinate axes, then write the value of

If the tangent line at a point (x, y) on the curve y = f(x) is parallel to y-axis, find the value of

Write the coordinates of the point on the curve y² = x where the tangent line makes an angle with x-axis.

Write the angle made by the tangent to the curve x = e^t cos t, y = e^t sin t atwith the x-axis.