Which expression provides the measure of angle n? tan (7/6) tan (6/7) tan -1(7/6) tan -1(6/7)

Hello from MrBillDoesMath!

tan ^(-1)  (6/7), the last expression in the list

Discussion:

In a right triangle,

tan(@) = side opposite angle\side adjacent to angle.

In our triangle, this becomes

tan(@) = LM \ MN =  6/7 =>

@ is the inverse tangent of (6/7)

Regards,  

MrB

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