Answer:
10cos(5x)sin(10x) = 5[sin (15x) + sin (5x)]
Step-by-step explanation:
In this question, we are tasked with writing the product as a sum.
To do this, we shall be using the sum to product formula below;
cosαsinβ = 1/2[ sin(α + β) - sin(α - β)]
From the question, we can say α= 5x and β= 10x
Plugging these values into the equation, we have
10cos(5x)sin(10x) = (10) × 1/2[sin (5x + 10x) - sin(5x - 10x)]
= 5[sin (15x) - sin (-5x)]
We apply odd identity i.e sin(-x) = -sinx
Thus applying same to sin(-5x)
sin(-5x) = -sin(5x)
Thus;
5[sin (15x) - sin (-5x)] = 5[sin (15x) -(-sin(5x))]
= 5[sin (15x) + sin (5x)]
Hence, 10cos(5x)sin(10x) = 5[sin (15x) + sin (5x)]
1 + tan ² Ф=sec²Ф
1+(12/5)²=sec²Ф
169/25=sec² Ф
sec Ф=⁺₋√(169/25)=⁺₋13/5
sec Ф=1/cos Ф ⇒cosФ=1/sec Ф
cos Ф>0 ⇔ sec Ф>0 ⇔ sec Ф=+ 13/5
cos Ф=1/secФ
cos Ф=1 / 13/5=5/13
we can calculate the sin Ф, with this method.
sin²Ф + cos²Ф=1 ⇒ sin Ф=⁺₋√(1-cos² Ф)
sin Ф=⁺₋√[1-(5/13)²]=⁺₋12/13
like cos Ф>0 and tan Ф>0 ⇒ sin Ф>0 ⇒sin Ф=12/13
answer: d.12/13
other method
tan Ф=sin Ф / cos Ф
12/5=sin Ф / 5/13
sin Ф=(12/5)*(5/13)=12/13
answer: d.12/13
Answer:757.02
Step-by-step explanation:
#26 right?
35x + 140 = 1050
-140 -140
<u>35</u>x = <u> 910
</u>35 35
x = 26 weeks
Answer:
Number of quarters → 15
Number of dimes → 2
Step-by-step explanation:
Let the number of dimes I have = y
And number of quarters = x
Since, I have amount in my pocket = $2
Therefore, 0.10y + 0.25x = 2
100(0.10y + 0.25x) = 100×2
25x + 10y = 200
5x + 2y = 40
2y = -5x + 40
y = -2.5x + 20 ---------(1)
Total number of coins in my pocket = 17
x + y = 17
y = -x + 17 ---------(2)
By using a graphing calculator we can graph these two lines (As attached)
Solution of the given system of equations will be the point of intersection of these lines.
Solution → (2, 15)
Number of quarters → 15
Number of dimes → 2
