Answer:
√10 / 10
Step-by-step explanation:
tan θ > 0 and sin θ < 0, so θ is in quadrant III. That means cos θ < 0.
cos(θ + π/4)
Use angle sum formula.
cos θ cos(π/4) − sin θ sin(π/4)
½√2 cos θ − ½√2 sin θ
Factor.
½√2 cos θ (1 − tan θ)
½√2 cos θ (1 − 2)
-½√2 cos θ
Write in terms of secant.
-½√2 / sec θ
Use Pythagorean identity (remember that cos θ < 0).
-½√2 / -√(1 + tan²θ)
-½√2 / -√(1 + 2²)
½√2 / √5
√10 / 10
Answer:
z = -12
Step-by-step explanation:
The given system of equations is:
xy/(x + y) = 1 ...........................(1)
xz/(x + z) = 2...........................(2)
yz/(y + z) = 3...........................(3)
From (1): x + y = xy
=> y = xy - x
y = x(y - 1)
x = y/(y - 1).......................................(4)
From (2): 2(x + z) = xz
=> 2x + 2z = xz
2x = xz - 2z
2x = z(x - 2)
z = 2x/(x - 2) ....................................(5)
From (3): 3(y + z) = yz
=> 3y + 3z = yz
3y = yz - 3z
3y = z(y - 3)
z = 3y/(y - 3)....................................(6)
Comparing (5) and (6)
2x/(x - 2) = 3y/(y - 3)
2x(y - 3) = 3y(x - 2)
2xy - 6x = 3xy - 6y
6(y - x) = xy .................................(7)
But from (1): xy = x + y
Using this in (7), we have
6(y - x) = x + y
6y - y - 6x - x = 0
5y - 7x = 0
5y = 7x
x = 5y/7................................................(8)
Using this in (4)
5y/7 = y/(y - 1)
1/(y - 1) = 5/7
(y - 1) = 7/5
y = 1 + 7/5
y = 12/5..........................................(9)
Using this in (8)
x = 5(12/5)/7 = 12/7 .......................(10)
Using (10) in (5)
z = 2x/(x - 2)
z = 2(12/7) ÷ (12/7 - 2)
= 24/7 ÷ -2/7
= 24/7 × (-7/2)
= -24/2 = -12
z = -12.
Answer:
8*4*3/2=48 i believe that this is correct if not im sorry
Step-by-step explanation:
180cm. The square is 6 x 6 = 36 and the triangles = 12 x 6 = 72 and then divide it by 2 = 36 multiply that by 5 and you get 180cm
