Chapter 1.2, Problem 77AYU

To determine

The value of a

Answer to Problem 77AYU

  $a=-4,1$

Explanation of Solution

Given:

The given equation is

  $y=x^2+3x$

Calculation:

The given point is (a, 4), therefore,

  $\begin{array}{l}y=x^2+3x\\ 4={\left(a\right)}^2+3a\\ a^2+3a-4=0\\ a^2+4a-1a-4=0\\ a\left(a+4\right)-1\left(a+4\right)=0\\ a=-4,1\end{array}$