Select The Correct Answer.The Variable S S S Varies Directly As The Square Of T T T . When S = 4 S = 4 S = 4 , T = 12 T = 12 T = 12 . Nick's Work Finding The Value Of T T T When S = 48 S = 48 S = 48 Is Shown:$[ \begin{aligned} s & = K

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Understanding Direct Variation

Direct variation is a relationship between two variables where one variable is a constant multiple of the other. In mathematical terms, if yy varies directly as xx, then y=kxy = kx for some constant kk. In this problem, we are given that the variable ss varies directly as the square of tt, which can be written as s=kt2s = kt^2.

Given Information

We are given that when s=4s = 4, t=12t = 12. This information can be used to find the value of the constant kk.

Finding the Value of kk

To find the value of kk, we can substitute the given values of ss and tt into the equation s=kt2s = kt^2. This gives us:

4=k(12)24 = k(12)^2

Simplifying the equation, we get:

4=k(144)4 = k(144)

Dividing both sides by 144, we get:

k=4144k = \frac{4}{144}

Simplifying further, we get:

k=136k = \frac{1}{36}

Nick's Work

Nick's work in finding the value of tt when s=48s = 48 is shown below:

s=kt248=136t248×36=t21728=t21728=t144×12=t1212=t124×3=t12×23=t243=t\begin{aligned} s & = kt^2 \\ 48 & = \frac{1}{36}t^2 \\ 48 \times 36 & = t^2 \\ 1728 & = t^2 \\ \sqrt{1728} & = t \\ \sqrt{144 \times 12} & = t \\ 12\sqrt{12} & = t \\ 12\sqrt{4 \times 3} & = t \\ 12 \times 2\sqrt{3} & = t \\ 24\sqrt{3} & = t \end{aligned}

Evaluating Nick's Work

Nick's work is correct, but it can be simplified further. We can start by simplifying the square root of 1728:

1728=144×12\sqrt{1728} = \sqrt{144 \times 12}

This can be further simplified by recognizing that 144 is a perfect square:

144×12=144×12\sqrt{144 \times 12} = \sqrt{144} \times \sqrt{12}

Simplifying the square root of 144, we get:

144=12\sqrt{144} = 12

So, we can rewrite the equation as:

1212=t12\sqrt{12} = t

We can further simplify the square root of 12 by recognizing that it is a perfect square:

12=4×3\sqrt{12} = \sqrt{4 \times 3}

Simplifying the square root of 4, we get:

4=2\sqrt{4} = 2

So, we can rewrite the equation as:

12×23=t12 \times 2\sqrt{3} = t

Simplifying further, we get:

243=t24\sqrt{3} = t

Conclusion

Q: What is direct variation?

A: Direct variation is a relationship between two variables where one variable is a constant multiple of the other. In mathematical terms, if yy varies directly as xx, then y=kxy = kx for some constant kk.

Q: What is the equation for direct variation when one variable varies as the square of another?

A: The equation for direct variation when one variable varies as the square of another is y=kx2y = kx^2.

Q: How do we find the value of the constant kk in a direct variation problem?

A: To find the value of the constant kk in a direct variation problem, we can use the given information to substitute into the equation and solve for kk.

Q: What is the relationship between the variables ss and tt in the problem?

A: The variable ss varies directly as the square of the variable tt, which can be written as s=kt2s = kt^2.

Q: How do we find the value of tt when s=48s = 48?

A: To find the value of tt when s=48s = 48, we can substitute the value of ss into the equation s=kt2s = kt^2 and solve for tt.

Q: What is the value of tt when s=48s = 48?

A: The value of tt when s=48s = 48 is 24324\sqrt{3}.

Q: How do we simplify the square root of 1728?

A: We can simplify the square root of 1728 by recognizing that 144 is a perfect square and that 12 is a perfect square.

Q: What is the simplified form of the square root of 1728?

A: The simplified form of the square root of 1728 is 121212\sqrt{12}.

Q: How do we further simplify the square root of 12?

A: We can further simplify the square root of 12 by recognizing that it is a perfect square.

Q: What is the simplified form of the square root of 12?

A: The simplified form of the square root of 12 is 232\sqrt{3}.

Q: What is the final simplified form of the value of tt when s=48s = 48?

A: The final simplified form of the value of tt when s=48s = 48 is 24324\sqrt{3}.

Q: What is the relationship between the variables ss and tt in the problem?

A: The variable ss varies directly as the square of the variable tt, which can be written as s=kt2s = kt^2.

Q: How do we find the value of the constant kk in a direct variation problem?

A: To find the value of the constant kk in a direct variation problem, we can use the given information to substitute into the equation and solve for kk.

Q: What is the equation for direct variation when one variable varies as the square of another?

A: The equation for direct variation when one variable varies as the square of another is y=kx2y = kx^2.

Q: What is direct variation?

A: Direct variation is a relationship between two variables where one variable is a constant multiple of the other. In mathematical terms, if yy varies directly as xx, then y=kxy = kx for some constant kk.