Question

boolean expression help using mathcad

Answer 1

Okay. Did you do 1a)? Let's see it.

Answer 2

for the the first problem my number that i'm supposed to do is 23 and so far I have x:=23 and as far as getting it to display a 1 i'm not sure of

Answer 3

is it x>23,2,1?

Answer 4

Well, you are testing against 30...

Answer 5

yes

Answer 6

I'm reading 30. Why do we care about 23?

Answer 7

because i have to compare my number to it and my number with an single boolean expression has to make a "1"

Answer 8

Yes, but you are comparing the assigned x to 23, not to 30.

Answer 9

i mean has to display a '1'

Answer 10

yes

Answer 11

You are not understanding your assignment at all. You must compare to 30. You must compare ALL values to 30. You can't just pull 23 out of a hat. It has to work for x = 23, sure, but it also has to work for EVERYTHING else.

Answer 12

oh okay so it should look maybe something like x:=23<30=1

Answer 13

Your assignment of a variable and the function that tests it do not need to be on one line. Just the expression for testing it is on one line.

Answer 14

Assign variable to any non-complex number.
Test variable with Boolean expression.
See result.

Answer 15

Why do you keep pulling out 23? Get that out of your head. There is nothing in the problem about 23.

Try this: \(f(x):=if(x<30,2,1)\)

Now, if you really want to, try \(f(23)\).

Answer 16

i'm forgetting what the set up for it is
y:=30,x^2,x^3 or y:= 30,2,1

Answer 17

You may need to spend more time with your user's manual. You do not seem to have a very good grip in the syntax.

Answer 18

@e.mccormick for the third prblem i have A
B(A+C)
EF
Q=A+B(A+C)+EF

Answer 19

Seriously, just write the expression I gave you and prove that it works.

What version of MathCad are you using?

Answer 20

This may help:
http://claymore.engineer.gvsu.edu/~jackh/eod/courses/egr345/media/mathcad.pdf

Someone else's short version:
http://www.engr.colostate.edu/ECE562/mathcad.pdf

They are named the same, but different files, so you may need to change a name to get both.

Answer 21

i don't have access to mathcad right now that's why i need serious help. if i had access to it i would understand it better because the examples are there

Answer 22

@tkbunny i'm using 3.0

Answer 23

Here's a plan. Go get access.

Actually, you're not using 3.0 since you don't have access. I presume that's Prime 3.0 and not the version from 1992, the original 3.0.

Answer 24

http://www.ptc.com/product/mathcad/free-trial/

Answer 25

for the first one 1a) i have it set up like f(x)=x<30)*23 is this correct?

Answer 26

for the first one 1a) i have it set up like f(x)=x<30)*23 is this correct? for 1b) i have f(x):=if(x<30,2,1)? and for 2a) i have
A
B(A+C)
EF
Q=A+B(A+C)+EF? are all off this correct?

Answer 27

this is a bit more specific then 'a boolean expression' i havent played in mathCad so im not going to be useful with this

Answer 28

for the first one i would be thinking something like

f(x) = 1 + (x ≥ 30)

Answer 29

but i dont know mathcad notation/ syntax

Answer 30

he only went over this once

Answer 31

f(23) = 1 + (23 ≥ 30)
= 1 + False
= 1 + 0
= 1

f(64) = 1 + (64 ≥ 30)
= 1 + True
= 1 + 1
= 2

Answer 32

@tkhunny and @e.mccormick read my last post am i correct about all three problems?

Answer 33

It is normally considered bad form to include Boolean calculations in the middle of an expression. If you are going to write something Boolean, then code it as Boolean.

\(f(x)=1+(x≥30)\) produces 2 for 30, 2 for > 30 and 1 for < 30. Is that what you want? It's not obvious by quickly glancing. You have to ponder it to see what it is doing. Plus, I would not consider this a "single Boolean expression".

\(f(x)=(x<30)∗x\) is just no good. This produces 0 for 30, 0 for > 30 and x for < 30. Plus, it's very ugly and very hard to understand. Seriously, just write what you mean. Write an expression that is easily understood.

\(f(x):=if(x<30,1,2)\) - Done. It is clear what this means. At a glance, it is clear. Unless there is some compelling argument about speed (which is unlikely), why would you do anything else? Some people like to make things LESS clear. I don't recommend that.

I'm not real clear on how the first two are different.

Boolean Expression: \(if(x<30,1,2)\)
Function: \(f(x) := if(x<30,1,2)\)

Answer 34

sorry for the confusion

Answer 35

and yes for the 2 problem i need to write it as A or B and C or C or E and F un like how i had it?

Answer 36

(A) or (B and (C or D)) or (E and F)

Why is "A" in the second expression?

Answer 37

oh s orry about that my mistake

Answer 38

@tkhunny thanks for your help