Integral in solve
07-13-2014, 06:05 PM
Post: #1
 lrdheat Senior Member Posts: 857 Joined: Feb 2014
Integral in solve
How would I set up an integral in solve app to, say, have integral x^2 from 0 to y = 20?
07-14-2014, 08:17 AM
Post: #2
 Joe Horn Senior Member Posts: 2,002 Joined: Dec 2013
RE: Integral in solve
(07-13-2014 06:05 PM)lrdheat Wrote:  How would I set up an integral in solve app to, say, have integral x^2 from 0 to y = 20?

Do you mean $$\int_0^{20}x^{2} dx$$ ? That's not an equation, it's just an expression. To evaluate an expression, just type it into Home or CAS; this one evaluates to 8000/3. The Solve app is for solving equations.

If I misunderstood your question, what equation you want to solve?

<0|ɸ|0>
-Joe-
07-14-2014, 08:38 AM
Post: #3
 eried Senior Member Posts: 745 Joined: Dec 2013
RE: Integral in solve
(07-14-2014 08:17 AM)Joe Horn Wrote:
(07-13-2014 06:05 PM)lrdheat Wrote:  How would I set up an integral in solve app to, say, have integral x^2 from 0 to y = 20?

Do you mean $$\int_0^{20}x^{2} dx$$ ? That's not an equation, it's just an expression. To evaluate an expression, just type it into Home or CAS; this one evaluates to 8000/3. The Solve app is for solving equations.

If I misunderstood your question, what equation you want to solve?

He says equals to 20, so it is an equation. Not solvable in the solver.

My website: ried.cl
07-14-2014, 12:44 PM
Post: #4
 CR Haeger Member Posts: 275 Joined: Dec 2013
RE: Integral in solve
(07-13-2014 06:05 PM)lrdheat Wrote:  How would I set up an integral in solve app to, say, have integral x^2 from 0 to y = 20?

In Solve App this seems to work okay (using Home variables X, T and the math template):

In CAS, you can use solve(), fsolve() to get a numerical or symbolic result

07-14-2014, 04:37 PM
Post: #5
 Tim Wessman Senior Member Posts: 2,293 Joined: Dec 2013
RE: Integral in solve
(07-13-2014 06:05 PM)lrdheat Wrote:  How would I set up an integral in solve app to, say, have integral x^2 from 0 to y = 20?

This works fine. However, if you tried this and it didn't work, it is probably because you accidentally did x^2d(x=20) instead of (x^2)dx =20

Make sure you press the right arrow once after to move out of the variable of integration template location before your =20.

TW

Although I work for HP, the views and opinions I post here are my own.
07-14-2014, 09:57 PM
Post: #6
 Anderson Costa Member Posts: 59 Joined: Apr 2014
RE: Integral in solve
(07-13-2014 06:05 PM)lrdheat Wrote:  How would I set up an integral in solve app to, say, have integral x^2 from 0 to y = 20?

It may be expressed for int(x^2,x,0,y)=20...
It's an Integral equation and is easily solved in Solve App!
07-15-2014, 02:09 AM
Post: #7
 lrdheat Senior Member Posts: 857 Joined: Feb 2014
RE: Integral in solve
I've tried the syntax (and other variations) suggested by Anderson, Tim, and CR. In each case, when I go into Num template and submit a guess, I get "bad guess(es)". Could I be in an odd operating mode?
07-15-2014, 02:48 AM
Post: #8
 eried Senior Member Posts: 745 Joined: Dec 2013
RE: Integral in solve
(07-15-2014 02:09 AM)lrdheat Wrote:  I've tried the syntax (and other variations) suggested by Anderson, Tim, and CR. In each case, when I go into Num template and submit a guess, I get "bad guess(es)". Could I be in an odd operating mode?

I get the same :/ that's why I said it was not solvable in that app. I tried with int and with the template too.

My website: ried.cl
07-15-2014, 06:09 AM
Post: #9
 Joe Horn Senior Member Posts: 2,002 Joined: Dec 2013
RE: Integral in solve
(07-15-2014 02:48 AM)eried Wrote:
(07-15-2014 02:09 AM)lrdheat Wrote:  I've tried the syntax (and other variations) suggested by Anderson, Tim, and CR. In each case, when I go into Num template and submit a guess, I get "bad guess(es)". Could I be in an odd operating mode?

I get the same :/ that's why I said it was not solvable in that app. I tried with int and with the template too.

See Tim's reply above. If you're using Textbook Entry mode, you have to press right-cursor between typing dX and typing =20.

<0|ɸ|0>
-Joe-
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