Y=kx^2
When x is doubled
Y=(2x)^2
Therefore Y=4x^2
Percentage increase=(3kx^2)/kx^2 ×100%
=300%
Is it good?
Y is directly proportional to the square of x.
Find the percentage increase in value of y when x is doubled
4 answers
correct, except I would keep the k in the calculation
old y = k x^2
new y = k (4x^2)
change in y = 3k x^2
percentage change = 3k x^2/(k x^2) = 3
or 300%
e.g. enter 1 and 4 for the following applet,
http://www.marshu.com/articles/calculate-percentage-increase-decrease-percent-calculator.php
old y = k x^2
new y = k (4x^2)
change in y = 3k x^2
percentage change = 3k x^2/(k x^2) = 3
or 300%
e.g. enter 1 and 4 for the following applet,
http://www.marshu.com/articles/calculate-percentage-increase-decrease-percent-calculator.php
Why is it 3x not 4x
I mean why is it 3k not 4K
2 answers