Question

Find the angle between a line parallel to X axis and the slope of graph
$y = \frac{x^{4}}{4}$
At X = 1.

(Combine differentiation and trigonometry).

Answer 1

$y = \frac{x^{4}}{4}$
dy/dx=x³
slope at x=1
dy/dx (at x=1) = 1³ = 1
tanA = 1
tanA = tan45°
=> A = 45°