Why square root of 42 is not rational number

Which function families have maximums and minimums? 1.)linear absolute value functions and exponential functions 2.) linear absolute value functions and quadratic functions 3.) linear absolute value functions and linear functions 4.) linear absolute value functions and constant functions

What is the quotient of m^6/5 ÷ 5/m^2? assume m does not equal pl

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.