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
<span>25x2 = 16
x^2 = 16/25
</span>x^2 = 4^2/5^2
<span>x = 4/5
</span>
Answer:
.
For values of x>0, it can be rewritten as 
Step-by-step explanation:
For the expression:

We can apply this logarithmical property: 
Then,

If we assume values of <em>x </em>> 0 (non negative values for x), then the expression could be rewritten as follows:
, since 
We have to remember that <em>domain</em> (all possible values x) for logarithmic function is for all x > 0, or mathematically expressed as:
Domain: 