Question

If y=kx^1/4​ and y=3√2 at x=81, what is the value of y at x=4?

a) y=2
b) y=√2
c) y=3
d) y=4

Answer 1

To find the value of y at x=4, substitute the given values into the equation y=kx^(1/4) and solve for k. Then substitute the value of k and x=4 into the equation to find the value of y, which is 2.

Step-by-step explanation:

To find the value of y when x=4, we can use the equation y=kx^(1/4).

Plug in the given value of y=3√2 at x=81 to find the value of k.

Then substitute the value of k and x=4 into the equation to find the value of y.

First, solve for k:

3√2=k(81)^(1/4)

3√2=k(3^4)^(1/4)

3√2=k*3^(4/4)

3√2=k*3^1

3√2=k*3=3k

So, k=√2.

Next, substitute the value of k and x=4 into the equation:

y=√2*(4)^(1/4)

y=√2*2^(1/4)

y=√2*√2

y=2