f(x)=sinx+cosx
getting really frustrated with my math teacher. gives us forumlas for things but then barely shows us how to use them if at all and then throws problems at that we have to make sense of ourself. why can't math teachers teach?
anyway, the question is express f(x)=sinx+cosx in...
tan(x-y)+tan(y-z)+tan(z-x)=tan(x-y)tan(y-z)tan(z-x)
I have redone this problem two or three times and all the steps just make my head spin. I've tried looking up tutorials online but they introduce things into the problem that we haven't been taught yet and that just confuses me more. Help!
So the question is...From point C on the ground level, the angle of elevation to the top of a tree is 30 degrees. From point D, which is closer to the tree, the angle of elevation is measured to be 45 degrees. Find the distance between points C and D if the height of the tree is 4m.
I know...
So I have a study guide for my final which was written by a different professor from my actual professor. So I don't understand the question, I don't know if it's because my professor did not teach this or if the wording is different from what I'm used to:
Find the square roots of 4*sqrt(3)+4(i)
Side lengths are a=6, b=6, c=4. Find the area
A=1/2*b*h
I split the triangle in half to find the height. Since the base is 4, that divided the base into 2:
2^2+h^2=6^2
4+h^2=36
h^2=32
h=4*sqrt(2)
===========
1/2*4*4*sqrt(2)=area of 8*sqrt(2)
Did I do this correctly? I do not have an...
Triangle ABC has area 25*sqrt(3). if Angle BAC=30 degrees, find |AC|=|BC|=?
the answer I got was 10*4th root(3)
Is this correct?
I am asking because someone other than my professor wrote the study guid for us for the final and I am not 100% sure what |AC|=|BC| means as my professor never...
So my professor gave us a study guide for the final but no there is no answer key. Could someone check my answers please?
Express cos(2 tan^-1(x/4)) and sin(2tan^-1(x/4) as an algebraic expression in x
I got:
cos(theta)=8*sqrt(x^2+64)/x^2+64
sin(theta)=x*sqrt(x^2+64)/x^2+64
So my math professor gave us a study guide for the final but he's not aloud to give us the answers so I have no idea if my answers are correct or not. So if a few people could let me know what they got after trying this that would be great.
If tan(theta) = -2[sqrt(2)], and theta is between 270...
Tomorrow is my math test and I'm going over the study guide:
I have vector U=<1, 3> and vector V=<5, 2>
It says let theta be the missing angle between the two vectors. What is the cos(theta) and sin(theta)?
I already know how to find the missing angle for cos(theta) but we never covered how...
My professor gave us a study guide with the solutions:
The equation is:
sec(theta)=2
I am supposed to convert it to a rectangular equation. I know the answer is going to be y^2-3(x)^2=0
I don't know how to get to the answer he gave us.
So the question is:
express (sqrt(2)/2 + sqrt(2)/2 i)^8 in a+bi form
I know r=1 and tangent=pi/4
Using the theorem i get 1(cos (2pi) +i*sin (2pi)) which becomes 1(1*i)=1*i however WebAssign says this is incorrect. I've also tried "0+1i" and just "i"
What am I doing wrong?
So we're learning to plot polar equations, which easy enough. But I got a question in the homework that wasn't covered in class:
Convert r=7cos(theta) into a rectangular equation. Use x and y values. I know how to convert when it's x=r*cos(theta) or y=r*sin(theta) and r and theta is given. But...
Convert the equation to polar form
8x=8y
I thought it would be
8*r*cos(theta)=8*r*sin(theta)
Said it was incorrect
then I thought I needed to divide by 8 to remove it, giving me:
r*cos(theta)=r*sin(theta)
But that was also incorrect and now I am stuck
Ok, So with this problem it says to use double angle or half angle formula. I have the formulas in my notes just not sure how to apply them to the problem I feel like I should be using the double formula though. Here's the problem:
cos(2*theta)+sin^2=0
I did that but I'm still lost. My professor emailed me back, said to square both sides the squared cos can be turned into sines using the pythagorean theorem identity. Which doesn't make sense to me because the pythagorean theorem identity still has cosines in it?
Sorry I'm replying so late.
Before I post the question I need to vent. I've about had it with my math professor. He isn't showing us how to solve problems that keep popping up in the math homework and I am 100% lost most of the time. Ok I'm done.
The question is
sec 3(theta)-2=0
I don't know how to solve this, we didn't really cover any problems like this in class
cos(1/2*cos^-1*x)
This is due tonight online and would like help please.
Answer wasn't correct for angle A but it was correct for angle c. Sorry it was sideways, that was just how it uploaded. Still not sure why I can't find angle A though when a=21 is opposite of angle A.
I've attached the problem and my work. When I enter cos^1(6.890625) I get an error, but 6.9 is also not the answer and Does Not Exist is also not an acceptable answer. So where I am going wrong with this?
Re: Word investment problem
I got 6700 for total amount invested and 2200 for unknown additional amount and it's still saying it's incorrect (online homework program)
Re: Word investment problem
I have no idea lol, the setup is what I came up with, we were just given the word problem. So I know my setup is wrong, but I don't know why or how to set it up correctly.
So I have an investment word problem that I have tried multiple times and have not been able to get the right answer.
"If Ben invests $4500 at 4% interest per year, how much additional money must he invest at 5.5% annual interest to ensure that the interest he receives is 4.5% of the total...
I don't know how to show it on here but I'll do the best I can.
So we have 4x^3-18x+4/ (x-2)
In synthetic division I used 4 0 -18 4 to divide by 2. I got 4x^2+8x-2 with remainder of 0. I applied the quadratic formula to 4x^2+8x-2 and got the answer -2 +/- sqrt{6} all over 2