V= x*(10-2x)(8-2x)
for greatest volume, differentiate v w.r.t x and equate to 0,
dv/dx= (10-2x)(8-2x) + x(-2)(8-2x)+ x(10-2x)(-2)=0
you get x from solving the quadratic equation. volume will be max at that x
We need to determinate who doesn't use anything, so first we must know the real number of who are practising: a person can do more things.
For doing this, is better use a three-circles graphic, but we try to do without it.
So
- 16 pool + gym + track, and this number is sure
- 38 gym + pool, but this number includes the people of 1st point. We must know who do only gym + pool: 38 - 16 = 22
- 31 pool + track, this number also includes people of 1st point, so: only pool + track 31 - 16 = 15
- 33 gym + track, this number also includes people of 1st point, so: only gym + track 33 - 16 = 17
now:
- 67 gym, we must know who use only gym: 67 - 16 (gym + pool + track) - 22 (gym + pool) - 17 (gym + track) = 12
- 62 pool, we must know who use only pool: 62 - 16 (gym + pool + track) - 22 (gym + pool) - 15 (pool + track) = 9
- 56 track, we must know who use only track: 56 - 16 (gym + pool + track) - 15 (pool + track) - 17 (gym + track) = 8
now we must now who do some facility: let's sum all
16 + 22 + 15 + 17 + 12 + 9 + 8 = 99
99/100 practise something
So only 1/100 doesn't use nothing
The probability is 1%
2m-4 = x+nx switch sides
2m-4 = x (1+n) common factor
2m-4/1+4 = x divide both side by 1-x
A) cos a = (√22)/5; tan a = (√66)/22
B) sin a = (2√2)/3; tan a = 2√2
C) sin a = (√30)/6; cos a = (√6)/6
D) sin a = 3/5; tan a = 3/4
E) sin a = (5√26)/26; cos a = (√26)/26
F) sin a = 3/5; tan a = 3/4
Explanation
The ratio for sine is opposite/hypotenuse. This means the side opposite the angle is √3 and the hypotenuse is 5. Using the Pythagorean theorem to find the adjacent side,
(√3)² + A² = 5²
3+A² = 25
A² = 22
A=√22
This means that cos a = adjacent/hypotenuse = (√22)/5 and tan a = opposite/adjacent = (√3)/(√22) = (√66)/22.
B) The ratio for cosine is adjacent/hypotenuse; this means the side adjacent to the angle is 1 and the hypotenuse is 3. Using the Pythagorean theorem to find the side opposite the angle (p),
1² + p² = 3²
1+p² = 9
p² = 8
p=√8 = 2√2
This means that sin a = opposite/hypotenuse = (2√2)/3 and tan a = opposite/adjacent = (2√2)/1 = 2√2.
C) The ratio for tangent is opposite/adjacent; this means that the side opposite the angle is √5 and the side adjacent the angle is 1. Using the Pythagorean theorem to find the hypotenuse,
(√5)²+1² = H²
5+1=H²
6=H²
√6 = H
This means that sin a = opposite/hypotenuse = (√5)/(√6) = (√30)/6 and cos a = adjacent/hypotenuse = 1/(√6) = (√6)/6.
D) The ratio for cosine is adjacent/hypotenuse; this means that the side adjacent the angle is 4 and the hypotenuse is 5. Using the Pythagorean theorem to find the side opposite the angle, p:
4²+p²=5²
16+p²=25
p²=9
p=3
This means that sin a = opposite/hypotenuse = 3/5 and tan a = opposite/adjacent = 3/4.
E) The ratio for tangent is opposite/adjacent;; this means that the side opposite the angle is 5 and the side adjacent the angle is 1. Using the Pythagorean theorem to find the hypotenuse,
5²+1²=H²
25+1=H²
26=H²
√26 = H
This means that sin a = opposite/hypotenuse = 5/(√26) = (5√26)/26 and cos a = adjacent/hypotenuse = 1/(√26) = √26/26.
F) 0.8 = 8/10; The ratio for cosine is adjacent/hypotenuse. This means that the side adjacent the angle is 8 and the hypotenuse is 10. Using the Pythagorean theorem to find the side opposite the angle, p:
8²+p² = 10²
64+p² = 100
p² = 36
p=6
This means that sin a = opposite/hypotenuse = 6/10 = 3/5 and tan a = opposite/adjacent = 6/8 = 3/4.
<span>f(x)=5x+3/6x+7
This means that f(6/x) = [</span>5(6/x)+3] / [6(6/x)+7] = [ 30/x +3 ] / [36/x +7]
If we assume x≠0 , f(6/x) = [30 +3x]/ [36 + 7x]
g(x)=√<span> [ x^2-4x ]
</span>
g(x-4) = √ [ (x-4)^2-4(x-4) ] = √ [ x² -8x +16 -4x +16 ] = √ [ x^2-12x +32]
