Recent content by niceboar

doesn't seem like it'd be right either looking at the answers 30C25 -> choose any 25 of the 30 25C4 -> all combinations of the 4 in the group of 25 so would it be 30C25 - 25C4? This isn't exactly an answer but there is 30C25 - 26C4 and 30C25 - 26C25 30C25 -> choose any 25 30-4 = 26 so 26C4...

oh would I do 29C24 + 28C23 + 27C22 + 26C21?

so part 2 of this problem is of the 25 how many groups have at least 1 calculator that needs to be recharged so I need 1 out of the 25 + 2/25 etc so 25C1 * 30C24 + 25C2 * 30C23 + 25C3 * 30C22 + 25C4 * 30C21 ? since I'd choose 1 out of 25 to be broken then choose the remaining 24 to be OK...

26C5 should equal 26C21 although looking at it that way seems more confusing

so 21 blank slots 4 are accounted for already (or the combination doesn't count) in the 25 so I would need to choose 21 calculators from 26 leftover? 26C21? Thank you.

the angle should be about 61 degrees you can graph it to verify on a graphing system if you want

seems like it

you wrote +2j and -j

-1*1 + -1*2 + 1*1 = -1 + -2 + 1 = -2

PQ dot PR = |PR| |PQ| cos theta (PQ dot PR) / (|PR| |PQ|) = cos theta should be right post what you got for PQ dot PR and the magnitudes

Homework Statement There are 30 calculators and a teacher selects a group of 25 of them. 4 of them need to be recharged. How many samples of the 25 calculators contain all 4 of the calculators that need to be recharged a. 30C4 b. 25C4 c. 30C25 d. 26C21 e. none Homework Equations nCr...

Yeah I'll try it out next homework problem

Yeah I didn't really see how you could get around that. So it's just to use KVL?

Okay makes sense. Why not just use diffeq?

i(t) is discontinuous, you can't integrate it. Or at least I don't know of a way. It's discontinuous since dv/dt at the flip of the switch goes positive to negative or vice versa.