bestie's question thread

[Bestie]

yea! I did something similar to that, but for the k I got -0.131243, cause I subbed in week 6 weight 45.5???

but the ans have something completely different from us:
w = 100.3(0.877)^t

[keltingmeith]

Man, where are you getting this practice application question from? Because I would not expect a specialist student to have to arrive at an answer like that. In fact, using excel, I'm getting that is pretty bloody accurate, which is almost identical to what you would've gotten.

[Bestie]

how is sin(2x +pi/2) equal to cos(2t)?

thanks in advance

[Phenomenol]

how is sin(2x +pi/2) equal to cos(2t)?

thanks in advance

sin(2x + pi/2) = sin(2(x + pi/4))
sin(2x + pi/2) is sin(2x) translated pi/4 units to the left, which graphically can be seen as equivalent to cos(2x). Try plotting both by hand and seeing for yourself.

Alternatively, use compound angles:
sin(2x + pi/2) = sin(2x)cos(pi/2) + cos(2x)sin(pi/2) = sin(2x)*0 + cos(2x)*1 = cos(2x)

[Bestie]

Find any w with non zero imaginary part that has magnitude w = 1 and Arg (w^7) = Arg(conjugate w^3)

thanks in advance