Can somebody do the rest of the letters of this for me the first ones i got are AEIF

Will give brainliest sum of arithmetic series (sigma notation) find the numerical answer to the summation given below. (image shown below)

How do you find the circumfrance of a circle?

Which function has an inverse function? a.f(x)= |x+3|/5 b. f(x)= x^5-3 c. f(x)= x^4/7+27 d. f(x)= 1/x²