## Algebra – Is this correct ? if not why ? thanks :)?

( 16 + 4 * 2 ) / ( 8 * 4 + 2 ) = 0.705 ???

I don’t think i did it right as 0.075 seems an odd number to be an answer ?

Also i could only do 24 / 34 with a calculator does anyone know an easy way to learn how to divide numbers like these. Thankyou 😉

No, you did not round it right, the number next to the 5 is above five so you need to round up, the answer is 0.706.

Just divide 34 into 24, which goes in 0 times, then put a point down a decimal point and then divide 34 into 240.
This goes in 7 times with 2 left over. Then do 34 divided by 20, as you have now put the remainder (2) over the next zero.
34 divided by 20 is again zero. So the 20 carries over to the next zero making 200. 34 goes into 200 five times with thirty left over. Then you do 34 divided by 30 plus another zero with is 300, the answer is 8. Then like i said before you round up because for numbers 5 or bigger make the decimal place before it round up, otherwise the number stays the same. Giving the answer 0.706.

0 0 .7 0 5 8
__________
2 2 3
4 2 0 0
34 : 2 4. 0 0 0 0

## TI-83+ Programming Question?

Ok so I’m programming a program to find the Y-Intercept of a line and its slope when inputting variables for X1, Y1, X2, Y2. Basically what I want to do is check and see if a number is even or odd and then divide it by 2 if it’s even, but not if it’s odd. This will in essence simplify my fraction. Is there any function on the calculator that can do this type of check for me?
Thanks

No, but it’s not difficult to write code yourself to do that.

Say the number is stored in X.
:If not(fPart(X/2
:X/2→X

Or if you want it all on one line (takes the same amount of memory, though – 13 bytes):
:X/(1+not(fPart(X/2→X

Edit: Oh hey! Kazuma brought up one of my answers from about a year ago that goes over a mod function workaround. You’d use that if you want to find the remainder of some division.

the questions are
1) the edges of three cubes are consecutive odd integers.If the cubes are stacked on a desk,as shown, the total exposed surface area is 381cm^2(squared).Find the lengths of the sides of the cube.

2) Antonella bought some calculators for a total of 240\$.She kept one for herself and sold the rest for 300\$ making a profit of 5\$ on each calculator.How many calculators did she buy?

1).
The edges of three cubes are consecutive odd integers.
If the cubes are stacked on a desk,
the total exposed surface area is 381 cm^2.
Find the lengths of the sides of the cube.
(x – 2), x and (x + 2)
The exposed area of the first cube = 4(x + 2)^2 – x^2
The exposed area of the second cube = 5x^2 – (x – 2)^2 – (x + 2)^2
The exposed area of the top cube = 5 (x – 2)^2
The total exposed surface area:
4(x^2 + 4x + 4) – x^2 + 5x^2 – (x^2 – 4x + 4) – (x^2 + 2x + 4) + 5(x^2 – 4x + 4) = 381
11x^2 – 2x + 28 = 381
11x^2 – 2x – 353 = 0
x = 1/11(1 – 2√971) = -5.5747
x = 1/11(1 + 2√971) = 5.7565
The lengths of the sides of
the cubes are 3.76, 5.76 and 7.76.

2).
Antonella bought some calculators for a total of \$240.
She kept one for herself and sold the rest for \$300
making a profit of \$5 on each calculator.
How many calculators did she buy?
Let x = „number bought“
(selling price) – (cost) = (profit)
(300/(x – 1)) – (240/x) = 5
300x – 240(x – 1) = 5x(x – 1)
300x – 240x + 240 = 5x^2 – 5x
5x^2 – 65x – 240 = 0
x^2 – 13x – 48 = 0
(x – 16)(x + 3) = 0
Antonella bought 16 calculators.

## tell whether “ “ is even odd or neither, show algebraically.?

the two functions are

y=secxtanx

&

y=1-sinx

need a lot of help…
very confused dont understand…
=[

i can do it with a calculator, but i need help showing it algebraically.

To start out you should know a few things…
If a function is even then f(-x) = f(x)
If a function is odd then f(-x) = -f(x)

You should also know that cos(x) is even; cos(-x) = cos(x)
You should also know that sin(x) is odd; sin(-x) = -sin(x)
The above are basic identities you should have from trig.

First one
f(x) = sec(x) tan(x)

Check f(-x) to see if it’s either even or odd
f(-x) = sec(-x)tan(-x)

You may know whether sec and tan are even or odd, or you may not. However know about cosine and sine so write it in terms of what you know
f(-x) = 1/cos(-x) * sin(-x) /cos(-x)

We know cos(-x) = cos(x)
f(-x) = 1/cos(x) * sin(-x) /cos(x)

And we know sin(-x) = -sin(x)
f(-x) = 1/cos(x) *-sin(x)/cos(x)

Put it back in terms of sec(x) and tan(x)
f(-x) = -sec(x)tan(x)

Well f(-x) is just -f(x) so it’s odd

For
f(x) = 1 -sin(x)
f(-x) = 1-sin(-x)
f(-x) = 1+sin(x)

Well it’s surely not even.. Is it odd?
If it was it would be -(1-sin(x)) or -1+sin(x) and it’s not.

So it’s neither..

## Calculus True/False Question?

I’m pretty confused right now, and I lost my calculator so I can’t look at a graph or anything, so any help would be appreciated.

Let f(x) be continuous, differentiable, and ODD, then

integral of f(x)dx = 0, with limits @ negative infinity and positive infinity

Is that True, or False?

I *THINK* that’s what it is, but I’m completely lost, so the reasoning to the answer is what would be most appreciated.