Q. Three points on the graph of the function f(x) are {(0,3),(1,9),(2,27)}. Which equation represents f(x) ?
Observe Pattern: Observe the given points to determine the pattern of the function.The points are (0,3), (1,9), and (2,27). We notice that as x increases by 1, the y-value seems to be multiplied by 3 each time. This suggests an exponential pattern.
Test Exponential Function: Test the hypothesis that the function is exponential. If the function is exponential, it could be of the form f(x)=a⋅bx. Since f(0)=3, we can determine the value of a because any number to the power of 0 is 1. So, a⋅1=3, which means a=3.
Determine Value of a: Use another point to determine the value of b. Using the point (1,9), we substitute x with 1 and f(x) with 9 in the equation f(x)=3⋅bx. We get 9=3⋅b1, which simplifies to b=39=3.
Verify with Third Point: Verify the function with the third point.Using the point (2,27), we substitute x with 2 and f(x) with 27 in the equation f(x)=3×3x. We get 27=3×32, which simplifies to 27=3×9=27. This confirms our function is correct.
More problems from Write a polynomial from its roots