Etermine the intervals on which the following function is concave up or concave down. identify any inflection points. f left parenthesis x right parenthesisf(x)equals=negative 5 x superscript 4 baseline plus 20 x cubed minus 5−5x4+20x3−5 determine the intervals on which the following functions are concave up or concave down. select the correct choice below and fill in the answer box(es) to complete your choice. (simplify your answer. type your answer in interval notation. use a comma to separate answers as needed.) a. the function is concave downdown on nothing and concave upup on nothing. b. the function is concave down on nothing. c. the function is concave up on nothing.

Idon’t even know the answer hehehehe

First, think of what you know. you know that the number t the end of the equation will need to be subtracted because it is the money he lost from buying the lawn mower. and your first two weeks have negative profit, so that tells you that c and d are wrong. now you can plug any of the weeks into a and b to see which one works. i'll start with plugging week 1 into a.this isn't right because it says your answer for week one should be -90.so now we need to try the same thing with b.this one got you the right answer, (sometimes if you only check with one of the weeks multiple will work so you need to check with more of the weeks, but it worked out fine here)this means that b is the correct answer.let me know if you need more clarification. i hope this : )