Which of the following statements is true?
2 answers:
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One
Remark
This is very complicate unless you pick the right method. It's very handy o know about substitutions.
Method
Let z = (k + 2)^2
Now the problem becomes
z + 16/z = 92 Multiply through by z
Solution
z^2 + 16 = 92z
That does not look very promising. If you know the quadratic formula, this mess can be solved. If you do not know what the quadratic formula is, then what I've written is the answer.
Worse yet, you have to know what complex numbers are. Is this something you know about? The z form of this equation is fine. It gives answers that are rational. The problem is that both are negative and so in your next step, you will be forced to take the square root of a negative number.
Maybe the answer is just
(x + 3)^ + 16 = 92(x + 3)^2
If all you have to do is expand this then you get
x^2 + 6x + 9 + 16 = 92(x^2 + 6x + 9) Remove the brackets.
x^2 + 6x + 25 = 92x^2 + 552x + 828 Put the left over to the right.
0 = 92x^2 - x^2 + 552x - 6x + 828 - 25
0 = 91x^1 + 546x + 803
It looks that way from the second question. If I'm wrong about that, put a comment down below.
Two
Put over a common denominator and expand
Remark
This is very complicate unless you pick the right method. It's very handy o know about substitutions.
Method
Let z = (k + 2)^2
Now the problem becomes
z + 16/z = 92 Multiply through by z
Solution
z^2 + 16 = 92z
That does not look very promising. If you know the quadratic formula, this mess can be solved. If you do not know what the quadratic formula is, then what I've written is the answer.
Worse yet, you have to know what complex numbers are. Is this something you know about? The z form of this equation is fine. It gives answers that are rational. The problem is that both are negative and so in your next step, you will be forced to take the square root of a negative number.
Maybe the answer is just
(x + 3)^ + 16 = 92(x + 3)^2
If all you have to do is expand this then you get
x^2 + 6x + 9 + 16 = 92(x^2 + 6x + 9) Remove the brackets.
x^2 + 6x + 25 = 92x^2 + 552x + 828 Put the left over to the right.
0 = 92x^2 - x^2 + 552x - 6x + 828 - 25
0 = 91x^1 + 546x + 803
It looks that way from the second question. If I'm wrong about that, put a comment down below.
Two
Put over a common denominator and expand
Answer:
138.06 lb N86.1°E
Step-by-step explanation:
There are several ways you can work this. One of the most straightforward is to resolve each vector into its north and east components, add those, and then covert the result back to magnitude and direction.
A diagram can help immensely.
We note that S78°E is the same as E12°S. Since we're used to seeing the coordinate system with the +x axis aligned with east, it can be convenient to think of the first force as 100 lb at -12°.
The angle of the second force is N53°E, which can be expressed as E37°N. Then in x-y coordinates, this force is 50 lb at +37°.
The components of the sum are the sum of the components:
R = F1 +F2 = (100cos(-12°) +50cos(37°), 100sin(-12°) +50sin(37°))
= (137.747, 9.300)
The the magnitude of the resultant is computed using the Pythagorean theorem:
||R|| = √(137.747² +9.300²) ≈ 138.06
and the angle is computed using the arctangent function. Here, our diagram tells us the angle is in the first quadrant, so is positive (relative to +x, or East).
∠R = arctan(9.300/137.747) ≈ 3.9°
__
We want to express the answer in terms similar to the way the given forces are expressed, so we want the angle relative to north. The resultant is then described by ...
R = 138.06 lb at N86.1°E
