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3 years ago

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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A machinist is allowed 1% tolerance on a shaft that measures 15 inches long. What is the amount of tolerance

Sauron [17]

Tolerance = 1% = 0.01 on a shaft of 15 in
Tolerance in inches = 15 x 0.01 =0.15 in
Since it' s a tolerance the acceptable error is either +0.15in or -0.15 in

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3 years ago

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Vlad [161]

Answer:

Step-by-step explanation:

1)4.5m+4.7=20m+47

4.5m-20m=47-4.7

-15.5m=42.2

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2)14+21w=7(2+3w)

41+21w=14+21w

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3)49r+35=7(7r+35)

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72h-27=72h-27

72h-72h=-27+27

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3 years ago

Use a calculator to solve this problem:<br><br> 28 + 27 × 36

Annette [7]

For this case we have that according to the order of algebraic operations PEMDAS, the multiplications have priority over the addition and subtraction, then, we have the following expression:

$28 + 27 * 36 =\\28 + 972 =\\1000$

Thus, the value of the expression is 1000.

Answer:

$28 + 27 * 36 = 1000$

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Please help me on this

Readme [11.4K]

For this case we have to define root properties:

$\sqrt [n] {a ^ n} = a ^ {\frac {n} {n}} = a$

In addition, we know that:

$a ^ {- 1} = \frac {1} {a ^ 1} = \frac {1} {a}$

On the other hand:

$4 ^ 2 = 16$

Thus, we can rewrite the given expression as:

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