If the pictured triangles are congruent what reason can be given

A metalworker has a metal alloy that is 15% copper and another alloy that is 60% copper. How many kilograms of each alloy shou

coldgirl [10]

18 kg of 15% copper and 72 kg of 60% copper should be combined by the metalworker to create 90 kg of 51% copper alloy.

Step-by-step explanation:

Let x = kg of 15% copper alloy

Let y = kg of 60% copper alloy

Since we need to create 90 kg of alloy we know:

x + y = 90

51% of 90 kg = 45.9 kg of copper

So we're interested in creating 45.9 kg of copper

We need some amount of 15% copper and some amount of 60% copper to create 45.9 kg of copper:

0.15x + 0.60y = 45.9

but

x + y = 90

x= 90 - y

substituting that value in for x

0.15(90 - y) + 0.60y = 45.9

13.5 - 0.15y + 0.60y = 45.9

0.45y = 32.4

y = 72

Substituting this y value to solve for x gives:

x + y = 90

x= 90-72

x=18

Therefore, in order to create 90kg of 51% alloy, we'd need 18 kg of 15% copper and 72 kg of 60% copper.

6 0

2 years ago

For what values of θ on the polar curve r=θ, with 0≤θ≤2π , are the tangent lines horizontal? Vertical?

Bond [772]

Given that $r=\theta$ , then $r'=1$

The slope of a tangent line in the polar coordinate is given by:

$m= \frac{r'\sin\theta+r\cos\theta}{r'\cos\theta-r\sin\theta}$

Thus, we have:

$m= \frac{\sin\theta+\theta\cos\theta}{\cos\theta-\theta\sin\theta}$

Part A:

For horizontal tangent lines, m = 0.

Thus, we have:

$\sin\theta+\theta\cos\theta=0 \\ \\ \theta\cos\theta=-\sin\theta \\ \\ \theta=- \frac{\sin\theta}{\cos\theta} =-\tan\theta$

Therefore, the values of θ on the polar curve r = θ, with 0 ≤ θ ≤ 2π, such that the tangent lines are horizontal are:

θ = 0

θ = 2.02875783811043

θ = 4.91318043943488

Part B:

For vertical tangent lines, $\frac{1}{m} =0$

Thus, we have:

$\cos\theta-\theta\sin\theta=0 \\ \\ \Rightarrow\theta\sin\theta=\cos\theta \\ \\ \Rightarrow\theta= \frac{\cos\theta}{\sin\theta} =\sec\theta$

Therefore, the values of θ on the polar curve r = θ, with 0 ≤ θ ≤ 2π, such that the tangent lines are vertical are:

θ = 4.91718592528713

3 0

3 years ago

A.no b.yes the question is in the picture

nevsk [136]

B. yes, it's a function

8 0

2 years ago

What is the solution to the inequality? −6x+5>−1

Bogdan [553]

Answer:

$\boxed{x$

Step-by-step explanation:

$-6x+5>-1\qquad\text{subtract 5 from both sides}\\\\-6x>-6\qquad\text{change the signs}\\\\6x$

3 0

2 years ago

1. Write out the law of cosines and find the hypotenuse of triangle with 2 sides lengths equal to three and the included angle m

LUCKY_DIMON [66]

Answer:

1.) $\sqrt{13.341}$ ≈ 3.652

2.) I would say something about how the A in front of cos in the equation would change to 90, rather than stay 75 (in the equation for the step by step), but it would be easier to just use the Pythagorean theorem.

Step-by-step explanation:

I think we may have the same class so hopefully this helps:

1.) $a^2 = b^2 + c^2 - 2bccosA$ --> law of cosines formula.

$a^2 = 3^2 + 3^2 - 2(3)(3)cos(75)$ --> plugged in numbers; when you draw the triangle, the included angle would be A, and the opposite side would be a. B and b, and C and c are opposite each other. In this case, a is the hypotenuse.

$a^2 = 18 - 18cos75$ --> in between steps.

$a^2 = 13.341$ --> more simplifying.

$a(hypotenuse) = \sqrt{13.341} or 3.652$ --> answer

2.) This one is just an explanation: The 75 in the equation is the given angle, which is a. If this changes, it would just change in the equation too. And obviously, if it's 90 degrees, you can just use Pythagorean theorem a^2+b^2=c^2.

Good luck! :)

6 0

2 years ago