The process of solving radical equations is essentially the same as solving a linear equation, that is, by using inverse operations. The inverse of a square root operation is squaring, and the inverse of an nth root, is to take the nth power.
It is important to note, however, that the solution to the equation itself can be negative.
When solving questions with real life applications, we also need to ensure we have viable solutions, which make sense within the context of the question. A non-viable solution does not make sense within the context of the question, such as a negative value when we are solving for the length of a physical object.
The process of solving radical inequalities is similar to solving a radical equation using inverse operations and properties to isolate the variable. However, there are two things to remember:
\displaystyle -2\sqrt{x} | \displaystyle < | \displaystyle -6 | |
\displaystyle \sqrt{x} | \displaystyle > | \displaystyle \dfrac{-6}{-2} | Division property of inequality: notice the sign is reversed |
We can solve radical inequalities algebraically, ensuring to test the solution set found is valid, or we can solve with technology by graphing or creating a table of values.
Solve the following equations:
\sqrt{y}+5=9
\sqrt[3]{4x-9}=-1
Solve each equation for x. Identify any extraneous solutions.
3x=1+2\sqrt{x}
\sqrt{x+17}=x+5
The radius r of a cone whose height is equal to twice its radius is given by r = \sqrt[3]{\dfrac{3V}{2 \pi}}. Carlos is studying an underwater volcano that is roughly this shape. Solve for the volume, V, of the volcano if it has a radius of 1.3\text{ km}. Give your answer in km^3, rounded to one decimal place.
Solve each inequality for x. Represent the solution set on a number line.
\sqrt{3x+12} \lt 6
-6\sqrt[3]{4x+20}\leq 12
\sqrt{3x-6}+1 \geq 2x-6, with technology