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rdf8585

macrumors regular
Original poster
Feb 15, 2006
129
0
I need to find the value of the exponential function y=2.50(3.50)^1.4x when x is = 2

Does that mean y=2.50(3.50)^1.42

or

y=2.50(3.50)^1.4(2)

???
 
<_<

>_>

I did not read this then run away. Ummm my battery died?

Edit: Actually thats not hard at all, I believe EricNau is correct
 
3. Solve this exponential equation for x: e^5x= 1 over e^2x+7

4. Solve this exponential equation for x: 2^4x-7=32

are these answers right?

3...... -1
4....... no idea........
 
savar said:
Huh?

2.50(3.50)^1.4(2)

Order of operations is ^ before *

I think Google knows algebra :D
I disagree. Look at the original problem: y=2.50(3.50)^1.4x. I don't think that's intended to be 2.50 * (3.50 ^ 1.4) * x. I think the product 1.4x is to be treated as the exponent, i.e., 2.50 * ( 3.50 ^ ( 1.4 * x ) ). But if you change x to a constant value, 2.50(3.50)^1.4(2), Google doesn't handle it way rdf8585's problem requires.

In other words, I would interpret 2 ^ 3 * 4 as (2^3)*4, as Google does, but I would interpret 2 ^ 3x as 2 ^ (3 * x) because with the juxtaposition implying implicit multiplication. So my point is that you have to add more parens to get the right answer from Google.
 
I wouldn't be using Google all that much to calculate my Algebra problems. I used to have Maple and that piece of software had so many options to solving any equation you could think of. I would know, I had to take a class that taught how to use the software, barely passed it. :eek:
 
Asking a mathematical question on MR is guaranteed to start a quarrel.

Its odd that Maths is so 'opinionated.'
 
It's my fault we're talking about math. I meant the discussion to be about teaching errors, but since my examples were about math, and I can't resist talking about math, I'll have to take the blame. :( :)
 
rdf8585 said:
3. Solve this exponential equation for x: e^5x= 1 over e^2x+7

4. Solve this exponential equation for x: 2^4x-7=32

are these answers right?

3...... -1
4....... no idea........

3) x = -1

4) x = 3
 
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