Search:

Well, the equations are not linearly independent, because the third can be derived as the sum of the first two. So, in essence, there are only two equations and three variables. For the equations...

If you just have one element, such as H, then you look at your handy periodic table and find the number underneath the atomic symbol. This number is the atomic weight (or molar mass), or the amount...

if you divide both sides of the first equation by 3 and both sides of the second equation by 2, you get:

x - 2y = 4
x - 2y = 4

Since these are both the same line, there are infinitely many...

well, to separate it out:

1 + tanx = 1 + sinx/cosx = cosx/cosx + sinx/cosx = (cosx + sinx)/cosx

so when this is divided by (sinx + cosx), the numerator cancels, leaving:

1/cosx = secx

Well, to start, the equation of the reaction is Mg + 2HCl = MgCl2 + 2(H+)
so the molar ratio of Mg: MgCl2 is 1:1

so we multiply the grams of magnesium by the inverse molar mass to get moles of...

Using half-reactions:
1(I2) + 6(H2O) = 2(HIO3) + 10(H+) + 10(e-)
1(HNO3) + 1(e-) + 1(H+) = 1(NO2) + 1(H2O)

Multiplying the bottom by 10 (to cancel out the electrons) yields

1(I2) + 10(HNO3)...

Okay, we can cancel MgF2 and NaF right away because they have bonds between metals and nonmetals, which are ionic and not covalent

N2 and F2 are both diatomic molecules where both atoms are the...

well, it is a trig identity that sin(a + b) = sin(a)cos(b) + sin(b)cos(a)... I do not know the proof off the top of my head

in that particular example, cos(b) = 0, so the sin(a)cos(b) term...

2cos^2(x) = sin(x) + 1
2(1 - sin^2(x)) = sin(x) + 1
2 - 2sin^2(x) = sin(x) + 1
0 = 2sin^2(x) + sin(x) - 1
0 = (2sin(x) - 1)(sin(x) + 1)
2sin(x) - 1 = 0 sin(x) + 1 = 0
2sin(x) = 1 ...

Hey, I know how messy trig can be, so you just have to remember to keep working at it, because a lot of practice really is the only way to improve.

1) using a and b for alpha and beta,...

Apparently a lot of people have the same problem as I do with forgetting childhood books. I think I may record all the books I read to my kids so this never happens to them!

There are a couple of...