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3 years ago

What is the value of the expression 1/2(6x9x1)+15

Mathematics

1 answer:

Vanyuwa [196]3 years ago

5 0

Answer:

the answer of the expression is 42

Step-by-step explanation:

PEMDAS parenthesis are first so we start out with 6x9x1 and the answer to that is 54, next is MULTIPLICATION so we take 1/2 times 52 which is 27 then next is ADD so we add 15 and the answer is 42

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Answers need help!!!!!!

Gala2k [10]

<h3>Step-by-step explanation:</h3>

<u>Pythagorus theorum:</u>

9² = 3² + YZ²

81 - 9 = YZ²

√72 = YZ

∴YZ= 8.48 ≈ 8.5

<u>Trigonometry:</u>

We have adjacent as 3, and hypotenuse as 9

cos X = 3/9

X= cos∧-1 (3/9) → <em>[cos inversed]</em>

∴X= 70.5°

We have opposite as 3 and hypotenuse as 9

sin Z= 3/9

Z= sin∧-1 (3/9)→<em> [sin inversed]</em>

∴Z= 19.47 ≈ 19.5

4 0

3 years ago

A scientist was in a submarine below sea level, studying ocean life. Over the next ten minutes, she went up 22.1 feet. How many

GaryK [48]

A scientist is actually stronger then u but okay

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3 years ago

Read 2 more answers

Find the surface area of a sphere<br> Show all the work

IrinaVladis [17]

Answer:

452cm2

Step-by-step explanation:

surface area of sphere =4πr2

so 4π62 which equals to 452.39.

hope this helps u understand:)

5 0

2 years ago

Please help with any of this Im stuck and having trouble with pre calc is it basic triogmetric identities using quotient and rec

german

How I was taught all of these problems is in terms of r, x, and y. Where sin = y/r, cos = x/r, tan = y/x, csc = r/y, sec = r/x, cot = x/y. That is how I will designate all of the specific pieces in each problem.

Let's start with sin here. $\frac{2\sqrt{5}}{5} = \frac{2}{\sqrt{5}}$ Therefore, because sin is y/r, r = $\sqrt{5}$ and y = +2. Moving over to cot, which is x/y, x = -1, and y = 2. We know y has to be positive because it is positive in our given value of sin. Now, to find cos, we have to do x/r.

cos = $\frac{-1}{\sqrt{5}} = \frac{-\sqrt{5}}{5}$

Let's start with secant here. Secant is r/x, where r (the length value/hypotenuse) cannot be negative. So, r = 9 and x = -7. Moving over to tan, x must still equal -7, and y = $4\sqrt{2}$ . Now, to find csc, we have to do r/y.

csc = $\frac{9}{4\sqrt{2}} = \frac{9\sqrt{2}}{8}$

The pythagorean identities are

sin^2 + cos^2 = 1,

1 + cot^2 = csc^2,

tan^2 + 1 = sec^2.

Let's take a look at the information given here. We know that cos = -3/4, and sin (the y value), must be greater than 0. To find sin, we can use the first pythagorean identity.

sin^2 + (-3/4)^2 = 1

sin^2 + 9/16 = 1

sin^2 = 7/16

sin = $\sqrt{7/16}$ = $\frac{\sqrt{7}}{4}$

Now to find tan using a pythagorean identity, we'll first need to find sec. sec is the inverse/reciprocal of cos, so therefore sec = -4/3. Now, we can use the third trigonometric identity to find tan, just as we did for sin. And, since we know that our y value is positive, and our x value is negative, tan will be negative.

tan^2 + 1 = (-4/3)^2

tan^2 + 1 = 16/9

tan^2 = 7/9

tan = - $\sqrt{7/9} = \frac{-\sqrt{7}}{3}$

Let's take a look at the information given here. If we know that csc is negative, then our y value must also be negative (r will never be negative). So, if cot must be positive, then our x value must also be negative (a negative divided by a negative makes a positive). Let's use the second pythagorean identity to solve for cot.

1 + cot^2 = $(\frac{-\sqrt{6}}{2})^{2}$

1 + cot^2 = 6/4

cot^2 = 2/4

cot = $\frac{\sqrt{2}}{2}$

tan = $\sqrt{2}$

Next, we can use the third trigonometric identity to solve for sec. Remember that we can get tan from cot, and cos from sec. And, from what we determined in the beginning, sec/cos will be negative.

$(\frac{2}{\sqrt{2}})^2$ + 1 = sec^2