Answer:
(i) the other two sides are 6 and 6
(ii) the other two sides are 
Step-by-step explanation:
(i) Sine: sin(θ) = Opposite ÷ Hypotenuse
Cosine: cos(θ) = Adjacent ÷ Hypotenuse
Tangent: tan(θ) = Opposite ÷ Adjacent
Here adjacent side = 6
opposite side = d
angle = 45°
other angles are 90° and 45°
tan (45) = Opposite ÷ Adjacent
1 = d ÷ 6
∴ d = 6 × 1 = 6
so opposite side = 6
Hypotenuse ² = opposite side ² + adjacent side²
= 6² + 6²
= 36 + 36
= 72
hypotenuse = 
= 6
the other two sides are 6 and 6
(ii) here adjacent side = 4√3
angle = 30°
other angles are 90° and 60°
opposite side = d
tan ( 30) = opposite ÷ adjacent
= d ÷ 4√3
= d × (
)
3 d = 4
therefore d = 
therefore opposite side =
Hypotenuse ² = opposite side ² + adjacent side²
=( )² +( 
)²
= 
therefore hypotenuse = 
=
the other two sides are 
As soon as I read this, the words "law of cosines" popped
into my head. I don't have a good intuitive feeling for the
law of cosines, but I went and looked it up (you probably
could have done that), and I found that it's exactly what
you need for this problem.
The "law of cosines" relates the lengths of the sides of any
triangle to the cosine of one of its angles ... just what we need,
since we know all the sides, and we want to find one of the angles.
To find angle-B, the law of cosines says
b² = a² + c² - 2 a c cosine(B)
B = angle-B
b = the side opposite angle-B = 1.4
a, c = the other 2 sides = 1 and 1.9
(1.4)² = (1)² + (1.9)² - (2 x 1 x 1.9) cos(B)
1.96 = (1) + (3.61) - (3.8) cos(B)
Add 3.8 cos(B) from each side:
1.96 + 3.8 cos(B) = 4.61
Subtract 1.96 from each side:
3.8 cos(B) = 2.65
Divide each side by 3.8 :
cos(B) = 0.69737 (rounded)
Whipping out the
trusty calculator:
B = the angle whose cosine is 0.69737
= 45.784° .
Now, for the first time, I'll take a deep breath, then hold it
while I look back at the question and see whether this is
anywhere near one of the choices ...
By gosh ! Choice 'B' is 45.8° ! yay !
I'll bet that's it !
Answer:
x < 3
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
Step-by-step explanation:
<u>Step 1: Define Inequality</u>
3x + 1 < 10
<u>Step 2: Solve for </u><em><u>x</u></em>
- Subtract 1 on both sides: 3x < 9
- Divide 3 on both sides: x < 3
Here we see that any value <em>x</em> smaller than 3 would work as a solution to the inequality.
