Answer:
The answer is given below
Step-by-step explanation:
The equation of a quadratic function is given by:
ax² + bx + c where a, b and c are the coefficients of the quadratic equation. The value of a determines whether the graph opens up or down (if a is positive opens up and if a is negative opes down), the value of c determines the y intercept (if c is positive, we have a positive intercept and if c is negative the intercept is negative).
The chosen equation is -x² -4x + 5. Since it has y-intercept of 5 and opens down (coefficient of x² is -1)
Let us assume a vertical stretch of 4, the new equation becomes:
4(-x² -4x + 5)
-4x² - 16x + 20
-4x² - 16x + 20 = 0
a = -4, b = -16 and c = 20
Using the quadratic formula:
[tex]x=\frac{-b \pm \sqrt{b^2-4ac} }{2a}\\ x=\frac{-(-16) \pm \sqrt{(-16)^2-4(-4)(20)} }{2(-4)}=\frac{16 \pm 24}{-8} \\x= -5 \ or \ x=1[/tex]
