# Help with some Math problems

## Recommended Posts

i was hoping that some people out there might be able to help me with a few of my math problems.

1) 2cos(x) = sqrt(2); Solve for x

2) Simplify log27-log8

3) 6e^3x = 3e^5x; Solve for x

4) Find the equation of an exponential function where f(2)=4 and f(5)=108

5) Find the polynomial with x-intercepts of 1 & 4, & y-intercept of -2

##### Share on other sites

RAINMAKA having been out of school for a while, it would be helpful if I knew what type of Math it is. Algebra or what?

calculus

##### Share on other sites

I'm on it, I'm assuming you are allowed to use a calculator?

##### Share on other sites

RAINMAKA is allowed, but your not water.

The problems with calculators is, it will never show your problem solving.

##### Share on other sites

I'm sorry RAIN, it has been too long since I did calc, I keep coming up with wrong answers.... I'll keep trying but for now it's a no go

##### Share on other sites

PM swimmer or Van, I bet they could do it!

They's the man!

##### Share on other sites

@ RAINMAKA

Here are my answers for some problems you 've posted (if i am allowed)

1) 2cos(x) = sqrt(2); Solve for x

ans.

2cos(x)=sqrt(2)

=1.414

therefore cos(x)=1.414/2=0.707

x=cos^-1(0.707)

=45.00865166

now comes

2) Simplify log27-log8

use calculator dude or longman tables if calcs are not allowed to find the values of both log 27 and log 8 and then find the difference

in my calculator there were both log to the base as exponential and to the base 10 i couldn't remember the default log base to be taken coz i am too out of school for a very long time!!!!!!!!!!!!!!!!!!!!!!

and

3) 6e^3x = 3e^5x; Solve for x

take log on both sides reducing it to 3x log 6 = 5x log 3

now simplify it dude and here too there is that base problem

4) Find the equation of an exponential function where f(2)=4 and f(5)=108

sorry dude i dont know how to do this!!!!!!!!!!!!!!!

finally

5) Find the polynomial with x-intercepts of 1 & 4, & y-intercept of -2

i am making out how can anyone make an equation with two x intercepts and one y intercept!!!!!!!!!!!!!!  and again sorry!!!!!!!!!!!!!!!!

hope you got the answers for atleast some!!!!!!!!!!!!!! q's!!!!!!!!!

pls correct me if i 'm wrong

##### Share on other sites

3) 6e^3x = 3e^5x; Solve for x

6e^3x=3e^5x

2e^3x=e^5x

2=e^5x.e^(-3x)

2=e^2x

taking log on both sides

ln(2)=2x

x=ln(2)/2

x=.34657

##### Share on other sites

Man that looks just like algebra, if I had known some of the abbreviations I could have solved some of it.

sqrt=square root

cos=??

^=??

I could do most of this in my head. Just not sure what most of it is.

##### Share on other sites

I live in dread of loosing a finger,
##### Share on other sites

If all else fails Roco, we just take off our shoes to count to 10 in the south.

##### Share on other sites

[

If all else fails Roco, we just take off our shoes to count to 10 in the south.

LOL I have heard the south can be a bit uncouth ,

##### Share on other sites

1) 2cos(x) = sqrt(2); Solve for x

x=pi/4

cos(pi/4)=sqrt(2)/2

2* (sqrt(2)/2) = sqrt(2)

um..yeah thts the only one i remember how to do lol

##### Share on other sites

@ wing zero

superb man its the best way to solve those type of q's

##### Share on other sites

thanks alot guys, with ur help i have figured them out

##### Share on other sites

Man, I would have had them done by X-mas for you. I promise.

##### Share on other sites

Man that looks just like algebra, if I had known some of the abbreviations I could have solved some of it.

sqrt=square root

cos=??

^=??

I could do most of this in my head. Just not sure what most of it is.

cos is cosine, ^ is exponential symbol..

##### Share on other sites

I don't  understand Greek

##### Share on other sites

Guess maybe it has been longer than I thought.

But I still beat most calculators for speed.

## Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

×   Pasted as rich text.   Paste as plain text instead

Only 75 emoji are allowed.

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
• Forums

• #### Extras

• My Results
×
• Create New...