Answer:
Does the correct answer necessarily HAVE to be one of those three options? Because I'm looking at the steps and there seems to no mistakes at all. Forgive me if I'm mistaken though!
Step-by-step explanation:
Adding both equations cancels y:
<span>4x + 8y = 16
</span><span>4x - 8y = 0
-----------------+
8x = 16 => x=2
filling in x=2 in the first equation gives:
4*2 + 8y = 16 => 8y = 8 => y=1
So (2,1) is the (x,y) pair that solves the two equations. Answer C.</span>
Answer:
answer is : Cos(13pi/8) = 0.3826
Step-by-step explanation:
We have, Cos (13pi/8)
Since 13pi/8 can be shown as 3pi/2 < 13pi/8 < 2pi
Hence 13pi/8 lies on fourth quadrant.
In fourth quadrant cosine will be positive.
Cos (13pi/8) = cos(3pi/2 + pi/8)
applying formula cos(A+B) = cos A cosB - sinAsinB
i.e Cos(3pi/2 + pi/8) = cos(3pi/2)cos(pi/8) - sin(3pi/2)sin(pi/8)
∵ Remember cos(3pi/2) =0 , sin(3pi/2) = -1
Cos(3pi/2 + pi/8) = 0 cos(pi/8) - (-1)sin(pi/8)
Cos(3pi/2 + pi/8) = 0 + 0.3826
Cos(3pi/2 + pi/8) = 0.3826
Hence we got Cos(13pi/8) = 0.3826
You go up 4 times and go to the left 2 times so the slope would be 4/-2
