SOLUTION: Use the function f(x)= 4x^2 + 4x - 15. Find the value of x that gives the minimum. For parts (b) - (d), refer to this number as m. b. Calculate f(m 1 1) and f(m 2 1).

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Use the function f(x)= 4x^2 + 4x - 15. Find the value of x that gives the minimum. For parts (b) - (d), refer to this number as m. b. Calculate f(m 1 1) and f(m 2 1).      Log On


   



Question 1179754: Use the function f(x)= 4x^2 + 4x - 15.
Find the value of x that gives the minimum. For parts (b) - (d), refer to
this number as m.
b. Calculate f(m 1 1) and f(m 2 1).

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

b.
f%28x%29=+4x%5E2+%2B+4x+-+15......equal to zero
+4x%5E2+%2B+4x+-+15=0....factor
+4x%5E2+-6x%2B+10x+-+15=0
+%284x%5E2+-6x%29%2B+%2810x+-+15%29=0
+2x%282x+-3%29%2B+5%282x+-+3%29=0
%282+x+-+3%29+%282+x+%2B+5%29=0
solutions:
%282+x+-+3%29+=0=>x=3%2F2
+%282+x+%2B+5%29=0=>x=-5%2F2
so, since x=m
m+%5B1%5D=3%2F2
m+%5B2%5D=-5%2F2