00:01
Okay, so looking at this problem, we've got which statement that is incorrect.
00:04
Hypotenuse is the longest side in the right triangle.
00:07
That is true.
00:08
Hypotenuse is always the opposite side of the 90 degrees.
00:10
That's true.
00:11
The pythagin theorem applies to all right triangles.
00:13
That's true.
00:14
You can solve for the end end side of any triangle.
00:16
This is the incorrect one.
00:17
If you know the lengths of the other two sides using paragraph, part c says it's for right triangles.
00:23
This is not for any triangles.
00:24
So that's where it goes wrong.
00:26
Give the figure on the right, which one is the angle of elevation? so if i look at point v, these two angles do match up right here and right here, but this is the angle of depression.
00:36
This is the angle of elevation.
00:40
So that is angle vst.
00:43
In triangle abc, a .b is 9.
00:45
B .c is 11.
00:46
Determine the tangent ratio of angle a.
00:49
So angle a is right here.
00:51
This is opposite.
00:52
This is adjacent.
00:54
So that means the tangent of a is equal to 11 divided by 9.
00:59
Now i do that.
01:02
I get 1 .22.
01:05
Okay, evaluate two times a sign of 30 plus four times cosine 60.
01:10
So let's see, we got sign of 30.
01:16
Sign of 30 comes out to one half.
01:18
So this will be two times one half plus four times cosine of 60 is one half again, minus three times.
01:31
It's going to be the reciprocal of the tangent of 45.
01:35
So tangent 45 is one.
01:37
So the cotentia is also one.
01:40
The sicken of 45 is going to be the reciprocal of the cosine.
01:45
So if i take cosine of 45 is equal to root 2, so cosine of 45 is root 2 over 2, meaning the sikin of 45 is going to be 2 over root 2.
01:57
Okay, which if i want to rationalize that, i can do that by doing this.
02:02
So that's going to give me 2 root 2 over 2, which cancels out to just a square root of 2.
02:09
So two times one half is, so sorry, that's going to be plus root two at the end.
02:14
Two times one half is one, four times one half is two, minus three plus the square of two.
02:20
Well, these are actually all cancel out, so my answer is just root two.
02:24
From a point in the ground, 7 .62 meters, 7 .62 meters from the foot of a tree, so 7 .62 is down here.
02:34
The angle of elevation to the top of the tree is 32 degrees.
02:37
Terming the height of the tree to the nearest hundred.
02:39
So i want to find this right here.
02:41
So according to 32 degrees, i'm setting up tangent.
02:45
So tangent of 32 is equal to h over 7 .62.
02:49
Multiplied 7 .62 to both sides.
02:52
So 7 .62 times the tangent of 32 is equal to my height.
02:57
So 7 .62 times the tangent of 32 gives me a height of 4 .76 meters.
03:05
From an airplane altitude of 1 ,500 meters.
03:09
So the altitude is 1 ,500.
03:11
The angle of depression to a rock on the ground is 29 degrees.
03:16
To determine the distance from the plane to the rock.
03:20
So the distance from the plane to the rock, i'm going to read that as this one here.
03:27
So we'll say it's that one we're looking for.
03:29
The angle of depression of the plane is the same as the angle of elevation here.
03:33
Okay.
03:34
So we're going to look at that as 29 degrees.
03:36
So we can set it up with sine.
03:37
Because sign of 29 is you go to, the opposite divided by the hypotenuse.
03:43
So when i solve this, i'm going to end up getting x is equal to 1 ,500 divided by the sign of 29.
03:50
So 1 ,500 divided by the sign of 29 gives me 3 ,094.
03:57
So this would be the straight line distance from the airplane to the rock.
04:02
Now it's referring to this distance, which nope, should not be because these are all bigger...