Louise wants to factorize completely the given polynomial
Grouping first, second terms together and third, fourth terms together
=
Taking common from first and second terms of the given expression and taking 5 common from the third and fourth terms.
=
Taking (x+3) common from the given expression,
= is the completely factored form.
The tangent to at the point (0, 5) has a slope equal to the derivative evaluated at
.
This tangent passes through the point (0, 5), so its equation is
The normal line passes through the same point, but is perpendicular to the tangent line, so its slope is the negative reciprocal of the slope of the tangent. So the equation for the normal line is