Atree casts a shadow 21 ft long. the angle of elevation of the sun is 51.what is the height of the tree

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb

70

step-by-step explanation:

2*5=10

4*15=60

60+10=

70

i hope this is what you were looking for.

see attached graph