Question

Is it just me or the wolfram sometimes wrong

Answer 1

Try to differentiate \[y=\frac{\sqrt{4t-1}}{3t-5}\]
and compare the answer with wolfram

Answer 2

not just you

Answer 3

i have seen it give rather bizarre and lengthy "show steps" for relatively simple integrals
i don't know if that counts as "wrong"

Answer 4

but sometimes it's hard to tell; they factor things in a crazy way sometimes

Answer 5

I have found wolf to be flat out wrong on multiple occasions, especially with DE's

Answer 6

The sign '+' or '-' switches in the denominator sometimes

Answer 7

this looks good though
http://www.wolframalpha.com/input/?i=sqrt%284x-1%29%2F%283x-5%29

Answer 8

This is what ive got for the equation on top
\[\frac{dy}{dt}=\frac{(3t-5)\frac{1}{2\sqrt{4t-1}}(4)-\sqrt{4t-1}(3)}{(3t-5)^{2}}\]
\[\frac{dy}{dt}=\frac{2(t-5)-3(4t-1)}{(3t-5)^{2}(4t-1)^{1/2}}\]
\[\frac{dy}{dt}=\frac{-10t-7}{(3t-5)^{2}(4t-1)^{1/2}}\]

Answer 9

it is fond of writing polynomials from the bottom up though.
a fairly natural thing to do if you think of power series

Answer 10

wolf's answer
\[\frac{-6 t-7}{(5-3 t)^2 \sqrt{4 t-1}}\]

Answer 11

i think you forgot the 2 up top

Answer 12

I nener use the quotient rule, product rule is always easier

Answer 13

never*

Answer 14

the 2?

Answer 15

\[\frac{dy}{dt}=\frac{(3t-5)\frac{1}{2\sqrt{4t-1}}(4)-\sqrt{4t-1}(3)}{(3t-5)^{2}}\times \frac{2\sqrt{4t-1}}{2\sqrt{4t-1}}\]

Answer 16

the 4 divide the 2

Answer 17

i think, i didn't do it with pencil and paper

Answer 18

looks like you forgot to multiply by 2

Answer 19

oh maybe a typo here
\[\frac{dy}{dt}=\frac{2(t-5)-3(4t-1)}{(3t-5)^{2}(4t-1)^{1/2}}\]

Answer 20

\[\frac{dy}{dt}=\frac{(3t-5)\frac{1}{\sqrt{4t-1}}(2)-\sqrt{4t-1}(3)}{(3t-5)^{2}}X\frac{\sqrt{4t-1}}{\sqrt{4t-1}}\]

Answer 21

i think you just dropped the 3 in front of the t in the first term

Answer 22

so i was wrong about the 2, but rather the error is
\[\frac{dy}{dt}=\frac{2(t-5)-3(4t-1)}{(3t-5)^{2}(4t-1)^{1/2}}\] should be
\[\frac{dy}{dt}=\frac{2(3t-5)-3(4t-1)}{(3t-5)^{2}(4t-1)^{1/2}}\]

Answer 23

2(3t-5) -(4t-1)3 = -6t-7

wolfram is right

Answer 24

Oh that's a noob move, forgot the 3, LOL

Answer 25

oh well, one for technology...

Answer 26

but still, the sign (3t-5) at the bottom for wolf is switched

Answer 27

it is squared

Answer 28

Yeah it doesnt matter

Answer 29

wolf likes
\[a_0+a_1x+a_x^2+...\] rather than the other way around

Answer 30

hmm never thought of that

Answer 31

Medals for all! :D