2cosx=2sin2x. Sin2x is an identity for 2sinxcos. So 2[2sinxcosx] gives you 4sinxcosx. 2cosx=4sinxcosx. Divide 2cosx on both sides and gives you 2sinx=0 and divide again, sinx=0. Sinx is 0 at 0 and 360 degrees, or pi and 2pi. So thats what x would be. 0,360,pi,2pi.
Answer:
4y = 3x + 4
3x-4y = -4 is correct
Step-by-step explanation:
This is what we do.
We first express the first equation in the form;
y = mx + c
where m represents the slope of the line
Thus we have;
4y = 3x -7
divide through by 4
y = 3/4x -7/4
Thus the slope here is the coefficient of x which is 3/4
Now, since the lines are parallel, it means that their slopes are equal
So the slope of the other line too is 3/4
We now use the point slope form to find the equation of this other line
Mathematically, that would be;
y-y1 = m(x-x1)
where (x1,y1) = (-4,-2)
Substituting this into the point slope equation, we have;
y-(-2) = 3/4(x-(-4))
y + 2 = 3/4(x + 4)
Cross multiply
4y + 8 = 3x + 12
4y = 3x + 12-8
4y = 3x + 4
For the answer to the question above, the easiest way to determine is changing every runner's speed into the same unit.
<span>First = 10 m/s </span>
<span>Second = 10 miles/min = 16090.34 / 60 m/s (As 1 mile = 1609.34 meter and 1 min = 60 sec) </span>
<span>Second = 260.82 m/s </span>
<span>Third = 10 cm/hr = 10*(0.01)/60*60 (As 1 cm = 0.01 m and 1 hr = 60*60 sec) </span>
<span>Third = 0.000028 m/s </span>
<span>Fourth = 10 km/sec = 10*1000 m/s (As 1 km = 1000 m and time is already in sec) </span>
<span>Fourth = 10000 m/s </span>
<span>So fastest would be the one who covers the largest distance in 1 sec. It would be the fourth one.</span>
5x-2=3x+8
X=5
That's your answer
