Subject: Math problem!

Same here. Though it was one of the easiest things at the 'higher' level of maths to learn :)

I will try to work it out:

tan(2 Arccot(1/2))= (2tan(Arccot(1/2)))/(1-tan²(Arccot(1/2)))

Because tan(Arccot(x))=1/x (if u want to, i can prove that too), you find that the result is -4/3

once again i need some help with math.
cosxcos2xcos4x=1/8
find x

I think the right way is to first get all down to cos(x)...so maybe use that cos(a+b) is cos(a)cos(b)-sin(a)sin(b) and sin(a+b) is cos(a)sin(b)+sin(a)cos(b) and after that use sin²(x) is (1-cos²(x)).

I come down to

16cos^7(x) - 24cos^5(x) + 10cos³(x) - cos(x) = 1/8

But right now don´t know how to go on.

Maple says the solution is Pi/3, so maybe that helps you...
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The beginning step is the half-angle formulas:

cos2x = 1 - 2sin²x
οr
cos2x = 2cos²x - 1

etc.

Well, you can do the math. =)

Terrier above has given you one of the final levels.

theres loadsa x's there... just answer like this

I have another mathematical problem I can't solve:

z^5=(z+1)^5

go and study than ;)

it has no real solution, imo.

it's very simple

solution it one (1)
1x1 = 1
5x1=1
1+5-6=0
(edited)

it's a funny pic, not a real problem

Quadratic equation

the solution could be like this

1 = (z+1)^5/z^5 = [(z+1)/z]^5

then

1 = (z+1)/z = 1+(1/z) -----> 1/z = 0 and it is true only if z = ∞

all most wizard man find very complicated solution, and the simple solution it's always not good
:)

I agree with dasanchez's solution, but the answer should be No real solutions (just as he said in the first place), because 1/z ~ 0 isn't the same as equal to 0.
(edited)

at school i learn one big lesson
in math is posible everything
one demonstration (i don't remember all) was when to start with 2 side of ecuation with same things, but following diferent way final result 1=2