#1

so my problem is:

(I don't know the code for "squared" so I'll just write 2)

b2 = (20)2 + (25)2 - 2(20)(25)(Cos 48)

So I keep getting

b2 = 1025 - 1338.3

but I get a negative number, which isn't right...

help?

(I don't know the code for "squared" so I'll just write 2)

b2 = (20)2 + (25)2 - 2(20)(25)(Cos 48)

So I keep getting

b2 = 1025 - 1338.3

but I get a negative number, which isn't right...

help?

#2

Awww I thought you put cousin law help meaning you got in trouble for incest and I was gonna say haha inbred because you misspelled cousin damn you for having math problems damn you to hell.

#3

Aww I hate disappointing thread titles.

#4

Squared= ^2

Can we see the original triangle?

Can we see the original triangle?

#5

your method seems logical, so the only thing i could think of is an imaginary solution, which doesn't seem like it would fit with the thing youre working on.... no idea

#6

Awww I thought you put cousin law help meaning you got in trouble for incest and I was gonna say haha inbred because you misspelled cousin damn you for having math problems damn you to hell.

. <----- See that? That's called a period. You should learn how to use it.

EDIT: And I just learned the cosine law about 2 weeks ago.

Unfortunately I can't remember it.

#7

Your value for cos 48 is wrong... cos 48 =0.669130606, 2*20*25*cos48 = 669.130606

Either your calculator was in radians or you didn't put some brackets.

Either your calculator was in radians or you didn't put some brackets.

#8

here's the triangle:

The answer is 18.9 cm, but I have to show how to get there.

I'm doing this: 40*50*Cos 48

The answer is 18.9 cm, but I have to show how to get there.

Your value for cos 48 is wrong... cos 48 =0.669130606, 2*20*25*cos48 = 669.130606

Either your calculator was in radians or you didn't put some brackets.

I'm doing this: 40*50*Cos 48

*Last edited by wylde_overdrive at Feb 18, 2008,*

#9

Your value for cos 48 is wrong... cos 48 =0.669130606, 2*20*25*cos48 = 669.130606

Either your calculator was in radians or you didn't put some brackets.

Listen to him (or her)

#10

here's the triangle:

The answer is 18.9 cm, but I have to show how to get there.

I'm doing this: 40*50*Cos 48

i though if you had 2 sides and the included angle it was 1/2 x side a x side b x cos included but i could be wrong

edit: nevermind, i think thats wrong, but i'll check

#11

and i thought geometry was confusing!

#12

Looks like your calculator is measuring in radians. Make sure mode is in degrees. So hit mode button until the little thing at the top says "deg" and not "rad".

#13

Looks like your calculator is measuring in radians. Make sure mode is in degrees. So hit mode button until the little thing at the top says "deg" and not "rad".

It is measuring in degrees.

#14

Wait.. if it's negative don't you type in the negative number, then 2nd cos (on the calculator)?

#15

theres nothing wrong with the information

just use the consine law rule, set your calculator to degrees

you should have

b^2=(25^2)+(20^2)-2(25)(20)cos(48)

and it equals

18.86cm

its all correct

How do I do the last part? is it 40 * 50 * 2x cos 48?

#16

just distribute the 2x25 and be done.... no more distributing, its like the 2 was in its own parenthesis isnt it? (2)(25)(20)(cos48)

#17

I figured it out. I was just entering the numbers in a different way.

#18

dude 2x20x25 definitely is not the same as 40x50. its the same as 40x25