# equations involving rational exponents problem

• Aug 5th 2011, 04:42 PM
mathmathmathmathmathmathm
equations involving rational exponents problem
(t - 1) ^-2/3 = 2

the answer is {4 - sqrt of 2 / 4}, {4 + sqrt of 2 / 4}

my steps:

1. raise each side a neg 3 to elimate neg 2

2. the 2 becomes 1/8

3. apply even root property

t-1 = + or - 1 / 2 times sq rt of 2 and from there i know i srewed up, any tips would be great
• Aug 5th 2011, 04:58 PM
BERMES39
Re: equations involving rational exponents problem
Try this way
• Aug 5th 2011, 05:15 PM
mathmathmathmathmathmathm
Re: equations involving rational exponents problem
i dont get how you went from step 2 to 3
• Aug 5th 2011, 05:32 PM
BERMES39
Re: equations involving rational exponents problem
Here it is in more detail
• Aug 6th 2011, 06:26 AM
mrmohamed
Re: equations involving rational exponents problem
Quote:

Originally Posted by mathmathmathmathmathmathm
(t - 1) ^-2/3 = 2

the answer is {4 - sqrt of 2 / 4}, {4 + sqrt of 2 / 4}

my steps:

1. Raise each side a neg 3 to elimate neg 2

2. The 2 becomes 1/8

3. Apply even root property

t-1 = + or - 1 / 2 times sq rt of 2 and from there i know i srewed up, any tips would be great

hi all
• Aug 6th 2011, 06:44 AM
SammyS
Re: equations involving rational exponents problem
Quote:

Originally Posted by mathmathmathmathmathmathm
(t - 1) ^-2/3 = 2

the answer is {4 - sqrt of 2 / 4}, {4 + sqrt of 2 / 4}

my steps:

1. raise each side a neg 3 to eliminate neg 2

2. the 2 becomes 1/8

3. apply even root property

t-1 = + or - 1 / (2 times sq rt of 2) and from there i know i screwed up. Any tips would be great.

The method in your Original Post looks fine as far as you went, with the addition of the above parentheses.

$\displaystyle t-1=\pm\frac{1}{2\sqrt{2}}$
$\displaystyle =\pm\frac{\sqrt{2}}{4}$
Therefore, $\displaystyle t=1\pm\frac{\sqrt{2}}{4}\,.$