Answer:
We use cosine rule also called cosine law which states
c^2=a^2+b^2-2abcosC
given
a=8cm, b=7cm, c=9cm cos C?
9^2=8^+7^2-2*8*7 cos C
expand
81=64+49-112 cos C
like terms together
81-113=-112 cos C
-32=-112cos C
multiply both sides by -1
32=112cos C
divide both sides by 112
32/112=cos C
cosC=0.2857
find cos inverse of 0.2857
angle C= 73.40
Answer:

Step-by-step explanation:
Answer:
9
Step-by-step explanation:
6+x, when x = 3
6+(3)
6+3=9
Answer:

Step-by-step explanation:
Given: 
Initial value: y(1)=6
Let 

Variable separable

Integrate both sides


Initial condition, y(1)=6


Put C into equation
Solution:

or



Hence, The solution is
or 