Early introduction to calculus, for beginning-algebra students

sinx

Junior Member
A small marshmallow is launched straight up in the air with a slingshot. Its height h in meters, relative to te ground, is given by the function h(t) = 5 + 20 - 5t^2, where t is measured in seconds. About when does the marshmallow reach its maximum height?
hint; max ht is when velocity=0.
v=dh/dt.

and as said previous you are missing a t.
h(t) = 5 + 20t - 5t^2

HallsofIvy

Elite Member
Since this was posted in "beginning algebra", taking the derivative is probably not appropriate. Instead "complete the square".

sinx

Junior Member
Since this was posted in "beginning algebra", taking the derivative is probably not appropriate. Instead "complete the square".
i'm confused.
If you set h(t)=0 and solve for t, you will get two times when ht =0.

mmm4444bot

Super Moderator
Staff member
… max ht is when velocity=0 …

i'm confused … [there are] two times when ht =0.

I'm a bit confused, too. Is the second 'ht' above an abbreviation of h(t) ?

Denis

Senior Member
I'm a bit confused, too. Is the second 'ht' above an abbreviation of h(t) ?
"English is the most ambiguous language in the world." ~ Yours Truly, 2018!