very simple, we use the formula sin(a+b)=sinacosb +
sinbcosa and sin(20)=2sinacosa
5pi = 2pi/3+3pi/3,
First, we use sin(a+b)=sinacosb + sinbcosa
sin(5pi/3)=sin(2pi/3+3pi/3)=
sin(2pi/3+pi)=
sin(2pi/3)cos(pi) +sin(pi)cos(2pi/3)
but we know that sin(pi)=
0, and cos (pi) = -1, so sin(5pi/3)=
- sin(2pi/3)
now, use sin(2a)=2sinacosa,
sin(5pi/3)= - sin(2pi/3)= -2sin(pi/3)cos(pi/3)
sin<span>(5pi/3)=
-2sin(pi/3)cos(pi/3)</span>
<span>sin(pi/3)= 0.86,
cos(pi/3)=0.5, finally we have </span>sin<span>(5pi/3)= -0.86 x 0.5= -0.43</span>
Answer:
- $8000 at 1%
- $2000 at 10%
Step-by-step explanation:
It often works well to let a variable represent the amount invested at the higher rate. Then an equation can be written relating amounts invested to the total interest earned.
__
<h3>setup</h3>
Let x represent the amount invested at 10%. Then 10000-x is the amount invested at 1%. The total interest earned is ...
0.10x +0.01(10000 -x) = 280
<h3>solution</h3>
Simplifying gives ...
0.09x +100 = 280
0.09x = 180 . . . . . . . subtract 100
x = 2000 . . . . . . divide by 0.09
10000 -x = 8000 . . . . amount invested at 1%
<h3>1.</h3>
$8000 should be invested in the 1% account
<h3>2.</h3>
$2000 should be invested in the 10% account
R=i/pt
R=1680/3000*8=1,680÷24,000
=0.07*100=7%
Answer:
Step-by-step explanation:
