SOLUTION: Can you help me find the domain for the following? f(x)=sqrt x-8 h(x)=3x^2+5x-3 m(x)=5/x^2-9 l(x)=5x-4 g(x)=7x+4/x+4

Algebra ->  Functions -> SOLUTION: Can you help me find the domain for the following? f(x)=sqrt x-8 h(x)=3x^2+5x-3 m(x)=5/x^2-9 l(x)=5x-4 g(x)=7x+4/x+4      Log On


   

Question 147476: Can you help me find the domain for the following?
f(x)=sqrt x-8
h(x)=3x^2+5x-3
m(x)=5/x^2-9
l(x)=5x-4
g(x)=7x+4/x+4
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
f(x)=sqrt(x-8)
All real numbers >=8 sqrt of negative numbers are not real (imaginary).
graph%28250%2C250%2C-50%2C50%2C-10%2C10%2Csqrt%28x-8%29%29
.
h(x)=3x^2+5x-3
all real numbers.
graph%28250%2C250%2C-10%2C10%2C-50%2C50%2C3x%5E2%2B5x-3%29%29
.
m(x)=5/(x^2-9)
5/(x+3)(x-3)
All real numbers except when x=3 or x=-3 (division by zero not allowed)
graph%28250%2C250%2C-10%2C10%2C-10%2C10%2C%285%2F%28%28x%2B3%29%28x-3%29%29%29%29
.
l(x)=5x-4
All real numbers.
graph%28250%2C250%2C-10%2C10%2C-10%2C10%2C5x-4%29
.
g(x)=7x+4/x+4
All real numbers except x=-4 (division by zero not allowed)
graph%28250%2C250%2C-10%2C10%2C-20%2C30%2C%287x%2B4%29%2F%28x%2B4%29%29
.
Ed