Recent content by veganazi

Homework Statement The experiment in my Physics lab today was to determine the mechanical advantage and efficiency of various pulley systems. My calculated work output is higher than my work input, which is causing an abnormally high value for efficiency, and I am attempting to find the source...

Um 2H2O + 2Cl(-) → O2 + 4H(+) + 6e(-)? Is this right?

Homework Statement Balance PbO2(s) + Cl(-) → PbCl2(s) + O2(g) Homework Equations n/a The Attempt at a Solution Pb(4+) + 2e(-) → Pb(2+) and I'm stuck because there's no 2nd reaction.

Homework Statement Establish the identity: 1+cos(2θ)+cos(4θ)+cos(6θ)=4cosθcos(2θ)cos(3θ) Homework Equations cos(a)+cos(b)=2cos((a+b)/2)cos((a-b)/2) The Attempt at a Solution I understand how to do a simple cos(+/-)cos problem according to the Sums as Products equations, but I am...

Homework Statement cos^-1(sin(5pi/4)) Homework Equations n/a The Attempt at a Solution I began by finding the reference angle of 5pi/4 by subtracting pi, and I got pi/4. pi/4 must be part of an isosceles right triangle, so I drew a diagram with sides 1,1, and √2. I found sin pi/4...

1/√(1-u^2) :smile:

I've got it now! Thank you so much! Your method is sooo much easier than the book is making it out to be.

I've still got you here. Wait. How do I know this by knowing the definition of cosine? I'm not given any values... I don't understand how I am supposed to find a 2nd side from one of the sides...

Okay, the first two things you said make sense. I am not getting how I am supposed to get the third side, as I'm not sure what values I am supposed to input into the Pythagorean theorem. I'm frustrated because I've been trying to work this problem for hours, and I'm still lost...

How am I supposed to find cos^-1 from drawing a right triangle?

Homework Statement csc(cos^-1 u) Homework Equations Fundamental identities properties The Attempt at a Solution The book is incredibly vague on how to do this. I tried multiplying csc by (cosθ/cosθ) to get cotθ*secθ. I'm not sure if this is the right thing to do, or what to do...

Haha, duh! Thanks.

Homework Statement csc^-1((2sqrt3)/3)Homework Equations csc^-1((2sqrt3)/3) = sin^-1(3/(2sqrt3))The Attempt at a Solution My Math Lab says I am supposed to use the equivalent sine function, so then I got sin^-1(3/2sqrt3). Then what do I do?