What is the larger fraction 8/9 or 12/13

Show algebraically that f and g are inverse functions f(x)=x^2/-6; g(x)=square root of 2x+12

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.

See attachment below and find the equivalent of tan(∠qsr)