1. Given any triangle ABC with sides BC=a, AC=b and AB=c, the following are true :
i) the larger the angle, the larger the side in front of it, and the other way around as well. (Sine Law) Let a=20 in, then the largest angle is angle A.
ii) Given the measures of the sides of a triangle. Then the cosines of any of the angles can be found by the following formula:

2.

3. m(A) = Arccos(-0.641)≈130°,
4. Remark: We calculate Arccos with a scientific calculator or computer software unless it is one of the well known values, ex Arccos(0.5)=60°, Arccos(-0.5)=120° etc
Answer:
-1/20
Step-by-step explanation:
2(3/8) - 4/5
6/8 - 4/5
30/40 - 32/40
-2/40
-1/20
Answer:
The answer is 364. There are 364 ways of choosing a recorder, a facilitator and a questioner froma club containing 14 members.
This is a Combination problem.
Combination is a branch of mathematics that deals with the problem relating to the number of iterations which allows one to select a sample of elements which we can term "<em>r</em>" from a collection or a group of distinct objects which we can name "<em>n</em>". The rules here are that replacements are not allowed and sample elements may be chosen in any order.
Step-by-step explanation:
Step I
The formula is given as

n (objects) = 14
r (sample) = 3
Step 2 - Insert Figures
C (14, 3) =
= 
= 
= 
= 364
Step 3
The total number of ways a recorder, a facilitator and a questioner can be chosen in a club containing 14 members therefore is 364.
Cheers!
cot(<em>θ</em>) = cos(<em>θ</em>)/sin(<em>θ</em>)
So if both cot(<em>θ</em>) and cos(<em>θ</em>) are negative, that means sin(<em>θ</em>) must be positive.
Recall that
cot²(<em>θ</em>) + 1 = csc²(<em>θ</em>) = 1/sin²(<em>θ</em>)
so that
sin²(<em>θ</em>) = 1/(cot²(<em>θ</em>) + 1)
sin(<em>θ</em>) = 1 / √(cot²(<em>θ</em>) + 1)
Plug in cot(<em>θ</em>) = -2 and solve for sin(<em>θ</em>) :
sin(<em>θ</em>) = 1 / √((-2)² + 1)
sin(<em>θ</em>) = 1/√(5)
The order of mathematical operation is MDAS.
M - multiplication
D - division
A - addition
S - subtraction
3 - 3 x 6 + 2
Multiplication : 3 x 6 = 18
Division: none
Addition : + 3 + 2 = 5 (combine positive numbers)
Subtraction : 5 - 18 = -13
3 - 18 + 2 = -13