Hello from MrBillDoesMath
Answer:
[email protected] = - sqrt(7)/ 4
which is choice B
Discussion:
This problem can be solved by drawing triangles and looking at ratios of sides or by using the trig identity:
([email protected])^2 + (sin2)^2 = 1
If [email protected] = 3/4
, the
([email protected])^2 + (3/4)^2 = 1 => (subtract (3/4)^2 from both sides)
([email protected])^2 = 1 - (3/4)^2 = 1 - 9/16 = 7/16
So...... taking the square root of both sides gives
[email protected] = +\- sqrt(7)/ sqrt(16) = +\- sqrt(7)/4
But is [email protected] positive or negative? We are told that @ is in the second quadrant and cos(@) is negative in this quadrant, so our answer must be negative
[email protected] = - sqrt(7)/ 4
which is choice B
Thank you,
Mr. B
Answer:
<h2>
Average speed is 15km/h</h2>
Step-by-step explanation:
Step one:
given data:
total distance =7.5km
time taken= 30 min= 0.5 hours
we know that the average speed is the average distance divided by time taken
Step two:
mathematically expressed as
speed=distance/time
substituting we have
speed=7.5/0.5
speed=15km/hour
Hence the average speed is 15km/h
6b6
——— (hope this helps)
ac2
Answer:
229.5
Step-by-step explanation:
In order to calculate the area of the arrow we need to calculate the area of the body of the arrow, and then the head of the arrow. The body of the arrow is a rectangle meaning that the area (Ar) can be calculated by multiplying the length by the height like so...
Ar = l * h
Ar = 11cm * 12cm
Ar = 132
Now we need to find the area of the head of the arrow, which is a triangle and therefore we can use the formula for the area of a triangle (At) which is height times base divided by 2...
At = 
At = 
At = 
At = 97.5
Now we simply add both areas together to calculate the total area of the arrow...
132 + 97.5 = 229.5
A simple way to turn this into an equation is by replacing the words with letters:
1464B = 3/4 S
Then you have to remove the 3/4 from the right side of the equation. You can do this by dividing both sides by 3/4:
1464 / 3/4 = S
Then you have to do the sum:
1464
/ 3
= 0488
488
X 4
= 1952
There are 1952 students.
