Homework Statement
I was asked to calculate the pH of .40M solution of NH4ClO4
but I wasn't given a Ka for it.
Homework Equations
The Attempt at a Solution
I dissciated NH4ClO4 into:
NH4(plus) and ClO4(minus)
but I"m stuck there. What am I doing wrong?
Homework Statement
What's the 39th derivative of cosx?
Homework Equations
1st dy/dx: -sin x
2nd: -cosx
3rd: sinx
4th; cosx
The Attempt at a Solution
So it repeats every 4
so I used 39/4 and for a remainder of 3 so is is the 3rd one down?
I got sin x but I don't know...
Homework Statement
is( X^2 )y + (Y^2)x = 6, then the second derivative at the point (1,3) is ?
Homework Equations
The Attempt at a Solution
I don't see how this is possible, when I plug in 1 and 3 it comes out as 9 = 6 which isn't true. Can someone tell me if this is wrong? or...
Homework Statement
A piece of iron weighing 85.65 grams was burned in air. The mass of the iron oxide produced was 118.37g.
1. Use the law of conservation of mass to calculuate the mass of oxygen that reacted with iron.
2. use the molar mass of oxygen to calculate the number of moles...
Homework Statement
Radiation with the wavelength 5.0x 10^-6 Meters belongs to what region of the spectrum ?
Homework Equations
None really.
The Attempt at a Solution
I don't really know how to read the spectrum too well, but it looks like Infared, am I right?
Homework Statement
A carbon-Oxegen double bond in certain organic molecules absorbs radiation that has a frequency of 6.0 x 10^13 s^-1
A. What is the wavelength of this radiation?
B. What is the energy of this radiation per photon? per mole of photons?
Homework Equations
The Attempt at a...
Yes, I did that and sin ^2x + Cos ^2X = 1
so that leaves me with sin^2x - cos^2x, which I have to simplify.
I turned that into (- cos^2x + Sin^2x) for simplification purposes.
Then I multiplied that whole thing by -1/-1
Which gave me Cos ^2x - Sin ^2x, which simplifies to Cos 2x...
1. Homework Statement [/b]
A cyclist is riding on a path modeled by f(x)= 0.08x where f and f(x) are measured in miles. Find the rate of change in elevation when x = 2
Homework Equations
(f(∆x + x ) - f(x))/∆x
∆x\stackrel{lim}{\rightarrow} 0
The Attempt at a Solution
I...
SO my final answer will be:
pi/4 + 2pi/4?
How would I do this for a repeating angle such as:
sin x = -1/2 or 1/2 with no limits? since the difference are different.
Like pi/6, 5pi/6, 7pi/6.
The differences are different.
Homework Statement
Tan^{2}X - 1 = 0
Homework Equations
The Attempt at a Solution
I added 1 to both sides, then I took the square root of both sides giving me:
tan x = \pm1
which gives me answers at pi/4, 3pi/4, 5pi/4 and so on.
Do I just write pi/4 + 2kpi as my answer?
so in this case would it be arcsin(sin(60)) = Arcsin ((\sqrt{3}/2
?
Can you give me a problem that displays what you have just told me? I'd really like to see one ( as I have not been told that in my Precalculus class).
Thanks.
yeah, its pi/6, 5pi/6, and so forth.
Whats the sign that I add to the answer if it's periodical? How exactly do I write the answer for this problem? Do I write all the radians that make the equation true one time around the unit circle then add the (periodical)?
Oh I think I get it.
So, I can take the arcsine of both sides in a problem such as:
sin(2x) = (Root3 )/2
and I would get arcsin(sin(2x)) = arcsin ((root3)/2)
Which would get me to 2x = arcsin ((root3)/2)?
Correct?
I understand from the point of a variation of the double angle formulas, but can you expliain your reasoning a bit to me?
I get two different answers from two different methods. It worries me hah.
Homework Statement
Sin ^{4}X - cos^{4}X
Homework Equations
The Attempt at a Solution
I'm just checking if I can switch the sin and cos at the beginning to make:
-Cos^{4}X + Sin^{4}X
Then multiply by -1 to basically switch the the Sin and Cos around?
I'm supposed to...
I'm still stuck. I used the inverse sin of the (root3)/2 and I got answers like pi/3, 2pi/3, ect.
I think I need to use the identity but it seems impossible to figure out:
2sinx cosx = (root3)/2