Question

if f(x) = 2(x)^2 + 5 square root (x+2), the domain for f(x) is all real numbers greater than or equal to

Answer 1

Hi Felicia!


`\rm f(x)=2x^2+5√(x+2)`

Remember that your square root function can only calculate positive values and zero. We can't put a negative under a square root.

This means that the "stuff" under the root must be greater than or equal to zero (positive).


`\rm x+2\ge0`

Solve for x in this equation, subtracting 2 from each side,


`\rm x\ge -2`

This is our domain, all x values -2 or larger.

Hope that helps! :)