College Algebra › Rational Exponents
Which of the following is equivalent to ?
Which of the following is equivalent to ?
When dealing with fractional exponents, keep the following in mind: The numerator is making the base bigger, so treat it like a regular exponent. The denominator is making the base smaller, so it must be the root you are taking.
This means that is equal to the fifth root of b to the fourth. Perhaps a bit confusing, but it means that we will keep
, but put the whole thing under
.
So if we put it together we get:
Evaluate.
Exponents raised to a power of <1 can be written as the root of the denominator.
So:
Recall that a square root can give two answers, one positive and one negative.
First, distribute the exponent to both the numerator and denominator of the fraction.
The numerator of a fractional exponent is the power you take the number to and the denominator is the root that you take the number to.
You can take the cubed root and square the numbers in either order but if you can do the root first that is often easier.
This is the answer. Alternatively, you could have squared the numbers first before taking the cubed root.
Solve for :
We can use the given property of rational exponents to solve for :
Evaluate the given rational exponent:
Rational exponents can be simplified by following this common rule:
We can apply this concept to the given value in order to evaluate:
Evaluate
can be seen as
, in a scientific calculator use the
button where
.
Solve for :
We can use the given property of rational exponents to solve for :
Evaluate:
Step 1: We need to understand what the fractional value in the exponent is.
A fractional exponent, , tells us that we must take the
th root of the number.
In this case, we have , so we will take the 4th root of
.
Step 2: Calculate...
The answer is .
Simplify:
An option to solve this is to split up the fraction. Rewrite the fractional exponent as follows:
A value to its half power is the square root of that value.
Substitute this value back into .
Evaluate
The denominator of the exponent "N" is the same as the "N" root of that number.
So