Question

If y is directly proportional to 2 x square and the difference in the value of y when x is equal to 1 and x is equal to 3 is 32 find the value of y when x is equal to minus 2

Answer 1

Step-by-step explanation:

y = 2kx², where k is a real constant.

We have:

2k(1)² - 2k(3)² = 32 or 2k(3)² - 2k(1)² = 32.

=> 2k - 18k = 32 or 18k - 2k = 32

=> -16k = 32 or 16k = 32

=> k = -2 or k = 2.

When x = -2,

y = 2(-2)(-2)² or y = 2(2)(-2)².

=> y = -16 or y = 16.