here's the image
but i dont know the answer
Answer:
Since, an airplane descended 4,000 feet before landing.
Now, we have to determine the integer which represents the number of feet, the airplane was above the ground before its descent.
Before the descent, airplane was at the height of 4,000 feet.
And the distance above the ground is represented by the positive integers and distance below the ground is represented by the negative integers.
Since, 4,000 feet is the distance of airplane above the ground.
So, the airplane was +4,000 feet above the ground before its descent.
The angle (2y - 5)° and 95° are vertical angles, then they are congruent, that is,
Solving for y:
The angle (3x + 55)° and 85° are vertical angles, then they are congruent, that is,
Solving for x:
Finally, the value of x + y is:
The answer in itself is 1/128 and here is the procedure to prove it:
cos(A)*cos(60+A)*cos(60-A) = cos(A)*(cos²60 - sin²A)
<span>= cos(A)*{(1/4) - 1 + cos²A} = cos(A)*(cos²A - 3/4) </span>
<span>= (1/4){4cos^3(A) - 3cos(A)} = (1/4)*cos(3A) </span>
Now we group applying what we see above
<span>cos(12)*cos(48)*cos(72) = </span>
<span>=cos(12)*cos(60-12)*cos(60+12) = (1/4)cos(36) </span>
<span>Similarly, cos(24)*cos(36)*cos(84) = (1/4)cos(72) </span>
<span>Now the given expression is: </span>
<span>= (1/4)cos(36)*(1/4)*cos(72)*cos(60) = </span>
<span>= (1/16)*(1/2)*{(√5 + 1)/4}*{(√5 - 1)/4} [cos(60) = 1/2; </span>
<span>cos(36) = (√5 + 1)/4 and cos(72) = cos(90-18) = </span>
<span>= sin(18) = (√5 - 1)/4] </span>
<span>And we seimplify it and it goes: (1/512)*(5-1) = 1/128</span>
Point c.
You can graph the two points in a calculator to find out the answer OR you can identify the lines using the y-intercept aka b in the y=mx+b format.
Y=x - 3 has a y-intercept of -3, so look for the line where it goes through -3 on the y axis. (do the same for the other except when the y-intercept is 1)
From this, you can identify the lines and just find where they intersect.
