2cos²x+cos x-1=0
cos x=t
2t²+t-1=0
t=[-1⁺₋√(-1+8)]/2=(-1⁺₋3)/4
We have two possible set solutions:
First set solutions.
t₁=(-1-3)/2=-4/4=-1
cos x=-1 ⇒x=cos⁻¹ (-1)=π +2kπ or 180º+360ºk (k=(...-2,-1,0,1,2...)
Second set solutions:
t₂=(-1+3)/4=2/4=1/2
cos x=1/2 ⇒ x=cos⁻¹ 1/2=π/3+2kπ U 5π/3+ 2kπ or
60º+360ºK U 300º+360ºK (k=...-2,-1,0,1,2,...)
solutions: first set solutions U second set solutions:
Answer in radians : π +2kπ U π/3+2kπ U 5π/3+ 2kπ (k=...-1,0,1,...)
Answer is degrees: 180º+360ºk U 60º+360ºK U 300º+360ºK (k=...-2,-1,0,1,2,...)
Answer:
I found the answer on this website. It seems correct! Link Below!
Step-by-step explanation:
Their both the answer hope this helps
Answer:
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Step-by-step explanation:
Find the distance between the three pairs first using the distance formula:

Take the first two points,
and insert the values:

Simplify parentheses (two negatives makes a positive):

The distance between the first two points is 5. Use the nest two points,
and insert values:

Simplify parentheses:

The distance between the nest two point is about 4.5. Use the remaining two points,
and insert values:

Simplify parentheses (two negatives makes a positive):

The distance between the last points is 5. Add the distances together to find the perimeter of the triangle:

The perimeter is about 14.5.