Question

help!! ~*~*~*~ fan n medal ~*~*~*~ !!!!!!!!!!!

Find AC. Round the answer to the nearest tenth. (image below!!!!)

Answer 1

ill get help @Keigh2015 @Mehek14

Answer 2

This is a classic example of the cosine rule

Do you know the cosine rule?

Answer 3

a^2+b^2=c^2 ?

Answer 4

no - htat is the Pythagoras rule

cosine rule is

a^2 = b^2 + c^2 - 2bc cos(A)

do oyu recognise that?

Answer 5

yes i do

Answer 6

so 1.3^2 is equal to x^2 + 1.1^2

Answer 7

OK - well you need to just get a handle on the meaning of a,b c and angleA and refer them to the values in your diagram

you are directly given in the drawing the equivalent of b, c and angleA

so oyu can use the formula as I gave it to solve for a (which is the side AC in your diagram)

Answer 8

put the values from your drawing into the diagram above

then use cosine formula to solve for a

Answer 9

hte formula you gave me makes no sense with te triangle

Answer 10

the**

Answer 11

That's why I said you need to understand the formula and what a,b,c and A mean

However my diagram above gives you more guidance

replace the values in your drawing with the letters in my diagram - THEN it corresponds with the formula.

Answer 12

x^2= 2.9

Answer 13

is as far as i got... - 2bc doesnt make any sense

Answer 14

so when I asked if oyu recognised the cosine rule you said yes
but it seems oyu don't

You need to review oyur notes or study "Cosine Rule" and understand it , before you can answer this question.

This is evidently the topic oyu are studying - so refer to your class , or your text, or search online - but you must understand it before you can answer this

Answer 15

will you attempt to explain?

Answer 16

I'm afraid I don't have time to go back to the beginning

the question is a classic example of the 'cosine rule' (sometimes called 'law of cosine' and allows you to solve a triangle when you know 2 sides and the include angle (as in oyur drawing).

The only slightly tricky bit is the 'nomenclature' i.e. which side is a,b ,c and which angle is A

look here for an explanation
https://en.wikipedia.org/wiki/Law_of_cosines
with the cosine rule and the sine rule you can solve nearly all problems about triangles