Solving Radical Equations

Solving Radical Equations
3
Solve the equation: 2 2π‘₯ βˆ’ 3 βˆ’ 22 = 0
3
2 2π‘₯ βˆ’ 3 = 22
3
Isolate the radical
3
2π‘₯ βˆ’ 3 = 11
Isolate the radical
2π‘₯ βˆ’ 3
3
= 11
3
2π‘₯ βˆ’ 3 = 1331
2π‘₯ = 1334
π‘₯ = 667
Cube both sides
Simplify
Solve for x
4
4
Solve the equation: 4π‘₯ + 3 = 2 π‘₯ βˆ’ 1
4
4π‘₯ + 3
4
4
= 2 π‘₯βˆ’1
4
Raise each side to the 4th power
4π‘₯ + 3 = 16(π‘₯ βˆ’ 1)
Simplify
4π‘₯ + 3 = 16π‘₯ βˆ’ 16
Distribute
19 = 12π‘₯
Solve for x
19
π‘₯=
12
Solve the equation:
5
(2π‘₯ +
2)2
5
5
= 3
(2π‘₯ + 2)2 = 3
5
Raise each side to the 5th power
(2π‘₯ + 2)2 = 243
Simplify
(2π‘₯ + 2)2 = 243
Square root
2π‘₯ + 2 = 15.588
Simplify
2π‘₯ = 13.588
π‘₯ β‰ˆ 6.794
Solve for x
Solve the equation:
5
(2π‘₯ + 2)2 = 3
(2π‘₯ + 2)2/5 = 3
((2π‘₯ + 2)2/5 )5/2 = (3)5/2
2π‘₯ + 2 = 15.588
2π‘₯ = 13.588
Re-write exponent as a fraction
Raise to the reciprocal power
Simplify
Solve for x
π‘₯ β‰ˆ 6.794
Alternative method using fractions as exponents.
𝑉
πœ‹β„Ž
r=
Solve for V:
2
π‘Ÿ =
𝑉
πœ‹β„Ž
π‘Ÿ2
𝑉
=
πœ‹β„Ž
2
πœ‹β„Žπ‘Ÿ 2 = 𝑉
Square each side
Simplify
Multiply by Ο€h
𝑉
πœ‹β„Ž
r=
Solve for h:
2
π‘Ÿ =
𝑉
πœ‹β„Ž
π‘Ÿ2
𝑉
=
πœ‹β„Ž
2
Square each side
Simplify
𝑉
=
πœ‹
Multiply by h
𝑉
β„Ž= 2
πœ‹π‘Ÿ
Multiply by r2
β„Žπ‘Ÿ 2
T = 2πœ‹
Solve for m:
𝑇
=
2πœ‹
𝑇
2πœ‹
2
=
π‘š
π‘˜
π‘š
π‘˜
π‘š
π‘˜
Isolate the square root
2
Square both sides
𝑇2
π‘š
=
2
4πœ‹
π‘˜
Simplify
𝑇2π‘˜
=π‘š
2
4πœ‹
Multiply by k
M = 2πœ‹
Solve for P:
3
𝑀
π‘ƒπ‘˜
=
2πœ‹
𝐿
𝑀𝐿
=
2πœ‹
𝑀𝐿
2πœ‹
3
=
3
π‘ƒπ‘˜
π‘ƒπ‘˜
𝐿
Isolate the cube root: divide by 2Ο€
π‘ƒπ‘˜
3
3
Isolate the cube root: mult. by L
3
Cube both sides
𝑀3 𝐿3
= π‘ƒπ‘˜
3
8πœ‹
Simplify
𝑀3 𝐿3
=𝑃
3
8πœ‹ π‘˜
Divide by k
The time T in seconds for a pendulum to complete one back-andforth swing is given by 𝑇 = 2πœ‹
𝐿
9.9
, where L is the length of the
pendulum in meters. Find the length of a pendulum that completes
one back-and-forth swing in 2.2 seconds.
𝑇
2πœ‹
=
2πœ‹
=
𝐿
9.9
𝑇2
𝐿
=
2πœ‹ 9.9
9.9𝑇 2
=𝐿
2πœ‹
9.9(2.2)2
2πœ‹
Isolate the square root
2
2
𝑇
𝐿
9.9
Square both sides
Simplify
Isolate L
= 𝐿, 𝐿 β‰ˆ 7.626 π‘šπ‘’π‘‘π‘’π‘Ÿπ‘  Substitute for T, solve