I need help with this problem​

This is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 5 terms.

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)

Jim had 3,067.48 in his checking account he wrote a check to pay for two airplane tickets. his account now has 1,845.24.