If y is directly proportional to the square of x, when x=4 y = 25, how do you find an expression for y in terms of x?

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Answer 1 · 2015-07-18T01:01:32

Find the quadratic expression.

y would be in the form: #y = ax^2 #

#25 = a(4)^2 # --> 25 = 16a --># a = 25/16#

The expression would be: #y = (25x^2)/16#

Check: x = 4 --> y = 25

Answer 2 · 2015-07-18T01:07:36

#y=1.562x^2#

#ypropx^2#

So:

#y=kx^2#

So:

#25=kxx4^2#

#k=25/16=1.562#

So:

#y=1.562x^2#