Question

solve for angle B. b=9, a=6, c=4

Answer 1

any diagram?

Answer 2

the formula for the law of consines in this question is

\[\cos(B) = \frac{a^2 +c^2 - b^2}{2ac}\]

sorry about the mistake before

Answer 3

i got \[Cos(B)=a ^{2}+7^{2}+9^{2}/2(a)(9)\]

Answer 4

it should be

\[\cos(B) = \frac{6^2 + 4^2 - 9^2}{2 \times 6 \times4}\]

and looking at the diagram, it will be the largest angle, since its opposite the longest side

Answer 5

a is not 6, you don't know a from what i'm seeing

Answer 6

so when you get the answer... the next step is to find the angle...

so it would be

\[B = \cos^{-1}(answer)..... or.......B = \arccos(answer)\]

depending on what you use to find an angle

Answer 7

opposite side of angle A is 6, a=6

Answer 8

i was looking at the wrong problem, yes a is 6 but i'm still confused haha i don't get this at all

Answer 9

campbell showed you the law of cosine, you just have to replace the variables

Answer 10

well the law of cosines is a standard formula...

the question is just about identifying the information and substituting it into the correct place,

Answer 11

i got -29/48=cos(B)

Answer 12

you'll need to use brackets

my method for input into a calculator is

\[(6^2 + 4^2 - 9^2) \div (2 \times 4 \times 6)\]

then you'll get a negative fraction answer...

Answer 13

great so on your calculator press shift or 2nd

then cos

then ANS

close the brackets

press equals and you should get the answer.

Answer 14

then ANS or answer keay just means you don't need to input the fraction again.

Answer 15

i don't think i'm right.. i got 0.82298

Answer 16

not quite

so what sort of calculator do you have...?

Answer 17

i forgot my calculator at school so at the moment i'm using mathway.com

Answer 18

ok... hold on

this online calculator will work.

http://web2.0calc.com/

press 2nd

then acos

then +- 29/48

close brackets...

and lastly the equals

Answer 19

127.168899655999

Answer 20

then to round that to the nearest 10th it would be 127.2 right?

Answer 21

yep thats great... well done

Answer 22

thank you so much! these take home tests are so hard for me

Answer 23

well remember if it take home... work with the formulas next to you...

good luck