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7 votes
7 votes
I need to understand the steps and why. ty.
√(y) ^4

User Asutosh
by
2.6k points

1 Answer

15 votes
15 votes

Answer:
y^2

Reason:

A square root represents an exponent of 1/2

So
√(y) = y^(1/2)

Raising that to the fourth power gets us this,


(√(y))^4 = (y^(1/2))^4\\\\ (√(y))^4 = y^((1/2)*4)\\\\ (√(y))^4 = y^(2)\\\\

----------------

Edit: Here's an alternative route


(√(y))^4 = (√(y))*(√(y))*(√(y))*(√(y))\\\\ (√(y))^4 = (√(y))^2*(√(y))^2\\\\ (√(y))^4 = y*y\\\\ (√(y))^4 = y^2\\\\

The first line is possible because raising anything to the 4th power is the same as having 4 copies of it multiplied out (eg: 3^4 = 3*3*3*3 = 81).

Then in the second line, I collected the terms into pairs

By line 3, the square root and squaring exponent cancel each other out. This only works if y is not negative.

User Joe Morgan
by
3.4k points
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