Answer:
Step-by-step explanation:
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
Answer:
Step-by-step explanation:
he is going adding 3 to each number ex.
5+3=8
8+3=11
11+3=14
14+3=17
and so on
The area of a trapezoid with base lengths 7 in and 19 in is given by
A = (1/2)(b1 + b2)h
A = (1/2)(7 +19)·7 = 91
The appropriate choice is
D. 91 in²
_____
It can also be figured by adding the area of the 7 in square (49 in²) to the area of the 7×12 in right triangle (42 in²).
To Euclid, a postulate is something that is so obvious it may be accepted without proof.
A. A straightedge and compass can be used to create any figure.
That's not Euclid, that's just goofy.
B. A straight line segment can be drawn between any two points.
That's Euclid's first postulate.
C. Any straight line segment can be extended indefinitely.
That's Euclid's second postulate.
D. The angles of a triangle always add up to 180.
That's true, but a theorem not a postulate. Euclid and the Greeks didn't really use degree angle measurements like we do. They didn't really trust them, I think justifiably. Euclid called 180 degrees "two right angles."
Answer: B C
