First we use sin(a+b)= sinacosb+sinbcosa
and cos(a+b)=cosa cosb -sinasinb
tan(x+pi/2)= sin(x+pi/2) / cos(x+pi/2)
and sin(x+pi/2) = sinxcospi/2 + sinpi/2cosx =cosx,
<span>cos(x+pi/2) = cosxcospi/2- sinxsinpi/2= - sinx,
</span> because <span>cospi/2 =0, </span>and <span>sinpi/2=1
</span><span>=tan(x+pi/2)= sin(x+pi/2) / cos(x+pi/2)= cosx / -sinx = -1/tanx = -cotx
</span>from where <span>tan(x+pi/2)=-cotx</span>
Answer:
Dylan delivered 140 parcels on Wednesday.
Step-by-step explanation:
On Wednesday:
On Wednesday, he delivered x parcels.
Thursday:
10% more than Wednesday, so 100 + 10 = 110% of x = 1.1x
Friday:
50% pless than on Thursday, so 100 - 50 = 50% of 1.1x = 0.5*1.1*x.
THis is equals to 77. So
Dylan delivered 140 parcels on Wednesday.
Answer:
The answers are A, C, & D.
Step-by-step explanation:
A: the 34 would have an imaginary 0 behind it, so then it would become 340, which is greater than 304.
B, C, D: same logic as A
Answer:
x = -5 or x = 5 (-1)^(1/3) or x = -5 (-1)^(2/3)
Step-by-step explanation:
Solve for x:
x^3 = -125
Taking cube roots gives 5 (-1)^(1/3) times the third roots of unity:
Answer: x = -5 or x = 5 (-1)^(1/3) or x = -5 (-1)^(2/3)
<span>1/5
This is a matter of elimination. So let's figure out how many of each display there is.
30% of 150 = 0.30 * 150 = 45 displays about electricity.
2/5 * 150 = 0.40 * 150 = 60 displays about renewable energy
1/10 * 150 = 150/10 = 15 displays about gas.
The rest of the displays are about nuclear power. So
150 - 45 - 60 - 15 = 30 displays about nuclear power. Since we want a fraction, we get 30/150
But 30/150 isn't in it's simplest form. The largest number that will evenly divide both 30 and 150 is 30. So divide both the numerator and denominator by 30
(30/30)/(150/30) = 1/5
So 1/5 of the displays are about nuclear power.</span>
