Q. If f(x)=7x−x2−2, what is the value of f(8), to the nearest tenth (if necessary)?Answer:
Substitute x with 8: Substitute the value of x with 8 in the function f(x). We have f(x)=7x−x2−2, so f(8)=7×8−(8)2−2.
Calculate numerator for x=8: Calculate the numerator of the function when x is 8. The numerator is −(8)2−2, which is −64−2=−66.
Calculate denominator for x=8: Calculate the denominator of the function when x is 8. The denominator is 7×8, which is 56.
Divide numerator by denominator: Divide the numerator by the denominator to find f(8). So, f(8)=56−66.
Simplify fraction for f(8): Simplify the fraction to get the value of f(8) to the nearest tenth.56−66 simplifies to approximately −1.1786, which rounds to −1.2 when rounded to the nearest tenth.