Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 Re: This is Cool » formulas of polynomials » 2016-02-20 08:32:49

I just discovered solving quadratic by "completing the square" so I explored cubic a bit and found this Method using "Depressing the cubic" (x = y - (b/3a)) and (y = s-t).

Curious if you guys prefer one method to the other in particular situations? Interesting stuff for us beginners.

#2 Re: This is Cool » formulas of polynomials » 2016-02-18 13:27:23

Wow. Cool to see that evolution.

#3 Re: Help Me ! » Factoring Tangent » 2016-02-18 12:53:39

While concept was forming in my head, I was wondering if functions could change (x + y)(x + y) (factoring) vs quadratic approaches so that factoring might work where it doesn't without tangents, cosines etc...However, I realized that doesn't really make sense so that quadratic equation was necessary.

That was sort of the rationale behind my original question. I realize it's sorta nonsense tho. Factoring clearly wasn't going to work. Unless I'm missing something else...which, of course, is very possible. Lol

#4 Re: Help Me ! » Factoring Tangent » 2016-02-18 12:40:57

Yup.

I just did x = b+/- blah blah to get tanx=.303 and -3.303.

So, tan^-1's =

16.86 degrees (.29 rad) and 196.86 degrees (pi+.29 rad).
And
286.84 degrees (1.28 + 2pi rad) and 106.84 degrees (pi - 1.28 rad).

#5 Re: Help Me ! » Factoring Tangent » 2016-02-18 10:58:15

Yes, that's what I meant. Thanks.

#6 Help Me ! » Factoring Tangent » 2016-02-18 10:00:45

Newman
Replies: 6

Can this be factored or do you have to do quadratic formula?? Does the fact that it's an angle give it any unique workable properties or do I just look at coefficients like any other quadratic? Thanks.

1tan^2x + 3tanx -1 = 0

#8 Re: Help Me ! » Factoring » 2016-02-17 18:09:07

And going back to this....is this right?? smile
Find y' when y=(x^3 + 3x^2 + 1)(x^2 + 2)

y'= 5x^4 + 12x^3+ 6x^2+ 14x

Thx

#9 Re: Euler Avenue » What had you learned today that you found interesting? » 2016-02-17 16:55:44

...and magic hexagon and unit circle. And started learning about I matrix vs 0 matrix. I actually learned (relearned) a heckload of math today. Haha! Now, I just have to practice it for 1000 hours so as not to forget. smile

#10 Re: Euler Avenue » What had you learned today that you found interesting? » 2016-02-17 16:49:50

I learned that they've gone out 10^14 and haven't found integers where a^3 + b^3 + c^3 = 33

#11 Re: Help Me ! » one more plz » 2016-02-11 18:06:01

thanks. for some reason, I wasn't putting together the fraction rel to sides of triangle. really appreciate it.

#12 Re: Help Me ! » One at a time hahaha » 2016-02-11 18:03:06

Thank you very much. Seems so obvious now. haha. Really appreciate it.

#13 Re: Help Me ! » Please help » 2016-02-11 15:38:26

Sheesh, they seem so freakin obvious now. Haha. Thank you so much again or ur efforts to help me!

#14 Re: Help Me ! » Please help » 2016-02-11 15:19:59

awesome! thank you. I'll study what u guyz posted. smile

#15 Re: Help Me ! » One at a time hahaha » 2016-02-11 14:43:30

Thanks.. Sorry, I freakin copied it wrong. Just fixed it!!

Eesh. Again, my apologies. I appreciate effort.

#16 Help Me ! » one more plz » 2016-02-11 14:21:15

Newman
Replies: 8

If sinθ = 3/5 and 0 ≤ θ ≤ pi/2, then tanθ = ??

Again, plz explain steps. Thank you!!

#17 Help Me ! » One at a time hahaha » 2016-02-11 13:46:34

Newman
Replies: 5

Okay, how bout this:

(2t-1)/(3t+4)=2

plz show steps
thx

#18 Re: Help Me ! » Please help » 2016-02-11 13:27:12

how? can u plz show work?

#19 Help Me ! » Please help » 2016-02-11 12:42:23

Newman
Replies: 6

Okay, a few of these are killin me. Please help and show work. Thank u so much!
#'s 1,3,4 and 6 please. So annoying because I can answer similar problems but missing some things...obviously.
THANKS!!
Test Guide

#20 This is Cool » PiperThesis » 2015-12-08 05:30:54

Newman
Replies: 0

This seems like it would be very amusing for people of all levels (don't let the first few words of paper scare ya, they're basically in jest). Curious what some of the chronic heavy math users think of it. Enjoy:
PiperThesis

http://www.theliberatedmathematician.com/wp-content/uploads/2015/11/PiperThesisPostPrint.pdf

#21 Re: Help Me ! » Factoring » 2015-09-29 15:37:53

Thanks again guys! Your perspective is more helpful than you might know. The language and approach is very grounding which is why I ask general questions sometimes. Great stuff.

#22 Re: Help Me ! » Factoring » 2015-09-29 09:35:48

Yeah, those two are a little advanced for me. I remember covering the stuff but it's been 20 years and I'm just beginning to relearn algebra. It's actually amazing how much one can remember after that long but the gaps are vast canyons. Haha.

#23 Re: Help Me ! » Statistics--HELP » 2015-09-29 09:23:07

Okay, I'll take a stab at 1 before somebody who actually knows tells ya. I could very well be wrong but I believe 2 standard deviations is defined as 95% are within mean. Since they gave you one standard deviation, I would guess that min height is 155cm and max is 175cm. Annnnnd BOY, could I be wrong. Haha!!

#24 Re: Help Me ! » Factoring » 2015-09-29 09:02:45

Okay, find the rational roots and if possible all roots:

2x^4 - x^3 - 11x^2 + 4x +12 = 0

And: Find y' when y=(x^3 + 3x^2 + 1)(x^2 + 2)

#25 Re: Help Me ! » Factoring » 2015-09-29 08:32:29

I was briefly looking ahead in a book I'm using to refresh on college algebra and saw some stuff in the section on functions that looked like there might be some weird factoring involved. I'll look again and post one. I'm guessing it probably wasn't factoring now that I think about it but...

Board footer

Powered by FluxBB