Big Ideas Math Algebra 1, 2015
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Big Ideas Math Algebra 1, 2015 View details
Chapter Test
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Exercise 16 Page 473

Practice makes perfect
a Before we begin, let's recall the definition of an even function.
We are asked to find values of a, b, and c, so that the function f(x)=ax^2+bx+c is even. Let's simplify the equation f(- x)=f(x) in the case of the given function.
f(- x)=f(x)
a(- x)^2+b(- x)+c=ax^2+bx+c
â–Ľ
Simplify
ax^2-bx+c=ax^2+bx+c
ax^2-bx=ax^2+bx
- bx=bx
0=2bx
0=bx
bx=0
Since equation bx=0 should be valid for all values of x, we get that b=0.
b Let's recall the definition of an odd function.
We are asked to find values of a, b, and c, so that the function f(x)=ax^2+bx+c is even. Let's simplify the equation f(- x)=- f(x) in the case of the given function.
f(- x)=- f(x)
a(- x)^2+b(- x)+c=- (ax^2+bx+c)
â–Ľ
Simplify
ax^2-bx+c=-(ax^2+bx+c)
ax^2-bx+c=- ax^2-bx-c
2ax^2+2c=0
ax^2+c=0
Since equation ax^2+c=0 should be valid for all values of x, we get that a=0 and c=0.
c From Part A we know that the function f is even if and only if b=0. From Part B we know that the function f is odd if and only if a=0 and c=0. Therefore, the function f is neither even nor odd if and only if values of a, b, and c are neither b=0 nor a=0 and c=0.