Question

If f(x) varies directly with x and f(x) = 72 when x = 6, find the value of f(x) when x = 3.

Answer 1

Answer:

The value of f(x)  at x = 6 is 36

Step-by-step explanation:

Given as :

f(x) varies directly with x

f(x) = 72  ,  for x = 6

So, The function f(x) must be 12 x

i.e f(x) = 12 x

A this function satisfy for x = 6

Now, The function is f(x) = 12 x

So, for x = 3

The function f(x) = 12 × 3

I.e  f(x) = 36

Hence The value of f(x)  at x = 6 is 36  Answer

Answer 2

Answer:

36

Step-by-step explanation:

Since f(x) varies directly with x, f(x) can be expressed alternatively as \[f(x) = k * x\] where k is a constant value.

Given that f(x) is 72 when the value of x is 6.

This implies, \[72 = k * 6\]

Simplifying and rearranging the equation to find the value of k:

k = \frac{72}{6}

Hence k = 12

Or, \[f(x) = 12 * x\]

When x = 3, \[f(x) = 12 *3 \]

Or in other words, the value of f(x) when x=3 is 36