Answer:
x ≥ -1/2
Step-by-step explanation:
We know that we cannot graph imaginary numbers. Therefore, our <em>x </em>value has to be greater than or equal to 0:
To find our domain, we need to set the square root equal to zero:
√(4x + 2) = 0
4x + 2 = 0
4x = -2
x = -1/2
We now know that no value below -1/2 can be used or we will get an imaginary number. Therefore, our answer is x ≥ -1/2
Alternatively, we can graph the function and analyze domain:
Step-by-step explanation:
We have
First, 125 is a perfect cube because
and
x^3 is a perfect cube because
so we can use the difference of cubes identity
Let say we have two perfect cubes:
64 because 8×8×8=64
and 27 because 3×3×3=27 and let subtract
we know that
but using the difference of cubes identity we should get the same thing.
Remeber cube root of 64 is 4 and cube root of 27 is 3 so we have
So the difference of cubes works for real numbers. This is a good way to help remeber the identity using real numbers.
Back on to the topic,
we know that 5 is cube root of 125 and x is the cube root of x^3 so we have