Question

If b is the mean proportion between a and c, then `(a^2 - b^2 + c^2)/(a^-2 - b^-2 + c^-2)` is equal to ______.

Options

• a⁴

• b⁴

• a²

• b²

Answer 1

If b is the mean proportion between a and c, then `(a^2 - b^2 + c^2)/(a^-2 - b^-2 + c^-2)` is equal to b⁴.

Explanation:

Since b is the mean proportion, b² = ac. Substituting ac = b² and simplifying the numerator and denominator gives the value b⁴.