Question 95559
Solve the following equations algebraically: 
t^(1/2)-2t^(1/4)-3=0 
I have worked this problem to a certain point. I am stuck and cannot get past. 
Here is my work: 
I made u equal t^(1/4) 
u^2-2u-3=0 
Factor to get:
(u-3)(u+1)=0
u = 3 or u=-1

t(1/4) = 3
t= 81 
OR
t^(1/4)=-1
Can't be.
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Check the t(1/4)=81 solution to make sure 
it is not extraneous
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