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ella [17]
3 years ago
8

What basic trigonometric identity would you use to verify that (sin2x + cos2x)/cosx=secx

Mathematics
2 answers:
Oksana_A [137]3 years ago
7 0

Answer:

Step-by-step explanation:

sin(2x) = 2 sin(x) cos(x) cos(2x) = cos2(x) – sin2(x) = 1 – 2 sin2(x) = 2 cos2(x) – 1. Now I am not sure if this is right but I remember another similar formula. Here is the correct formula cot x = cos x / sin x

2 ) ( sin² x + cos² x ) / cos x = sec x

1/cos x = sec x

sec x = sec x

cos² x + sin² x = 1

Papessa [141]3 years ago
3 0

Step-by-step explanation:

\frac{ \ {sin}^{2} x +  { \cos}^{2} x}{cos \: x}   = sec \: x \\  \\ LHS  \\ = \frac{ \ {sin}^{2} x +  { \cos}^{2} x}{cos \: x}    \\  \\  =  \frac{ 1}{cos \: x} \:( \because \:    \ {sin}^{2} x +  { \cos}^{2} x = 1) \\  \\  = sec \: x \\  = RHS \\

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Complete the steps to solve the inequality:<br><br> 0.2(x + 20) – 3 &gt; –7 – 6.2x
Zigmanuir [339]

answer: x > - 1.25

Step-by-step explanation:

0.2 •(x + 20)- 3> -7- 6.2x

0.2x + 1> - 7 - 6.2x

3 0
3 years ago
Un automóvil corre a 120 kilómetros por hora y otro a 80 kilómUetros por hora; si deben recorrer 960 kilómetros, ¿con cuántas ho
Artist 52 [7]

Answer:

4 hours

Step-by-step explanation:

The speed of the first car is

v_1 = 120 km/h

While the speed of the second car is

v_2=80 km/h

The time it takes for each car to cover a distance d is

t=\frac{d}{v}

where

d = 960 km is the total distance covered

For car 1, the time taken is:

t_1=\frac{960}{120}=8 h

For car 2, the time taken is:

t_2=\frac{960}{80}=12 h

Therefore, the difference in time is:

\Delta t =t_2-t_1 =12 -8 = 4 h

8 0
3 years ago
(15)Simplify the expression below. Show your work -(-7y+12)
kotykmax [81]
15. -(-7y + 12) = 7y - 12

16. 1/a = 16/18
      cross multiply
      16a = 18
      a = 18/16 = 9/8

17. 8x - 12 = 4x + 24
      8x - 4x = 24 + 12
      4x = 36
      x = 36/4
      x = 9

18. -6b > 42           4b > -4
       b < 42/-6          b > -4/4
       b < - 7              b > -1
so b < -7 and b > -1

19. 6 more then the product of 8 and n
      6 + 8n

20. 45 = 3b + 69
      45 - 69 = 3b
      -24 = 3b
      -24/3 = b
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6 0
3 years ago
Read 2 more answers
HELP !!! Evaluate f(-2) for the function f(x) = 3x2 + 2x - 5
Phoenix [80]

Answer:

3

Step-by-step explanation:

So we have the function:

f(x)=3x^2+2x-5

To evaluate the value of f(-2), substitute -2 for x. Thus:

f(-2)=3(-2)^2+2(-2)-5

Square first:

f(-2)=3(4)+2(-2)-5

Multiply:

f(-2)=12-4-5

Now, subtract:

f(-2)=8-5=3

So:

f(-2)=3

And we're done!

4 0
2 years ago
On a biology test, Travis got 29 questions correct but did not pass. On a second attempt, he got 38 questions correct. What was
maxonik [38]
Answer:
We know that his first attempt he got 29 questions correct, yet he didn’t pass & the second attempt he got 38 questions correct.
So, If i’m not wrong the percentage increase is 10% [Rounded].

Explanation:
38 - 29 = 9
9 rounded to the nearest tenth is 10%.
Forgive me if I’m wrong, good luck! ^^
3 0
3 years ago
Read 2 more answers
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