When two chords<span> intersect inside a circle, the product of the two segments of one </span>chord<span> equals the product of the two segments of the other chord.
</span><span>MN*NL=KN*LN
10x=4*20=80
x=8
ML=MN+NL=18
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Complete question :
Sam knows that his MP3 player has 40% of its battery life left and that the battery
charges by an additional 12 percentage points every 15 minutes. What percent of
the mp3's battery will be charged when Sam and his family leave? If mp3 was plugged in an hour before his family plan to leave.
Answer:
88%
Step-by-step explanation:
Time before leaving = 1hour
Current percentage = 40%
Charge rate = 12% every 15 minutes
Therefore,
Charge rate per minute :
12% / 15 = 0.8% per minute
Charge recieved after one hour (60 minutes) :
0.8% * 60
= 48%
Therefore, total charge after just before leaving is:
Current percentage + percentage received
40% + 48%
= 88%
This can be solver by creating a small equation with x being the number and solving for x. The equation would be 8 + 2( x + 3 ) = -6
Solve for x:
8 + 2( x + 3 ) = -6
Distribute the 2
8+ (2x+6)=-6
Subtract 8
2x+6= -14
Add 6
2x= 8
Divide by 2
x=4
So the number you are looking for is 4
I hope this helps!
Since sin(2x)=2sinxcosx, we can plug that in to get sin(4x)=2sin(2x)cos(2x)=2*2sinxcosxcos(2x)=4sinxcosxcos(2x). Since cos(2x) = cos^2x-sin^2x, we plug that in. In addition, cos4x=cos^2(2x)-sin^2(2x). Next, since cos^2x=(1+cos(2x))/2 and sin^2x= (1-cos(2x))/2, we plug those in to end up with 4sinxcosxcos(2x)-((1+cos(2x))/2-(1-cos(2x))/2)
=4sinxcosxcos(2x)-(2cos(2x)/2)=4sinxcosxcos(2x)-cos(2x)
=cos(2x)*(4sinxcosx-1). Since sinxcosx=sin(2x), we plug that back in to end up with cos(2x)*(4sin(2x)-1)
