Answer:
Lines BC and F represent perpendicular lines
Step-by-step explanation:
we have
<em>Line BC</em>
the slope of the line BC is 
<em>Line F</em>
the slope of the line F is 
we know that
If two lines are perpendicular, then the product of their slopes is equal to -1
so
we have
-----> slope line BC
-----> slope line F
Find the product of their slopes
therefore
Lines BC and F represent perpendicular lines
This revolves around exact trig values - no easy way to say this, you just need to memorise them. They are there for sin cos and tan, but I will give you the main tan ones below - note this is RADIANS (always work in them when you can, everything is better):
tan0: 0
tanpi/6: 1/sqrt(3)
tanpi/4: 1
tanpi/3: sqrt(3)
tanpi/2: undefined
Now we just need to equate -2pi/3 to something we understand. 2pi/3 is 1/3 of the way round a circle, so -2pi/3 is 1/3 of the way round the circle going backwards (anticlockwise), so on a diagram we already know it's in the third quadrant of the circle (somewhere between pi and 3pi/2 rads).
We also know it is pi/3 away from pi, so we are looking at sqrt(3) or -sqrt(3) because of those exact values.
Now we just need to work out if it's positive or negative. You can look up a graph of tan and it'll show that the graph intercepts y at (0,0) and has a period of pi rads. Therefore between pi and 3pi/2 rads, the values of tan are positive. Therefore, this gives us our answer of sqrt(3).
Y^2+5y+10
To 2 Squared go together the regular y go together and then normal go together
Answer:
Step-by-step explanation:
Probability refers to chance of happening of some event.
Conditional probability is the probability of an event A, given that another event B has already occurred.
denote the two boxes.
In box 
:
No. of black balls = 1
No. of white balls = 1
In box 
:
No. of black balls = 2
No. of white balls = 1
Let B, W denote black and white marble.
So, probability that either of the boxes is chosen is 
Probability that a black ball is chosen from box =
Probability that a black ball is chosen from box 
To find:probability that the marble is black
Solution:
Probability that the marble is black = 
