Answer:
Verified below
Step-by-step explanation:
We want to show that (Cos2θ)/(1 + sin2θ) = (cot θ - 1)/(cot θ + 1)
In trigonometric identities;
Cot θ = cos θ/sin θ
Thus;
(cot θ - 1)/(cot θ + 1) gives;
((cos θ/sin θ) - 1)/((cos θ/sin θ) + 1)
Simplifying numerator and denominator gives;
((cos θ - sin θ)/sin θ)/((cos θ + sin θ)/sin θ)
This reduces to;
>> (cos θ - sin θ)/(cos θ + sin θ)
Multiply top and bottom by ((cos θ + sin θ) to get;
>> (cos² θ - sin²θ)/(cos²θ + sin²θ + 2sinθcosθ)
In trigonometric identities, we know that;
cos 2θ = (cos² θ - sin²θ)
cos²θ + sin²θ = 1
sin 2θ = 2sinθcosθ
Thus;
(cos² θ - sin²θ)/(cos²θ + sin²θ + 2sinθcosθ) gives us:
>> cos 2θ/(1 + sin 2θ)
This is equal to the left hand side.
Thus, it is verified.
Answer:
∠AEC = 139°
Step-by-step explanation:
Since EC bisects ∠BED then ∠BEC = ∠CED = 4x + 1
∠AED = ∠AEB + ∠BEC + ∠CED = 180 ← straight angle
Substitute values into the equation
11x - 12 + 4x + 1 + 4x + 1 = 180, that is
19x - 10 = 180 ( add 10 to both sides )
19x = 190 ( divide both sides by 19 )
x = 10
Hence
∠AEC = ∠AEB + ∠BEC = 11x - 12 + 4x + 1 = 15x - 11, hence
∠AEC = (15 × 10) - 11 = 150 - 11 = 139°
60 is my resultados of area
The last one: the arc AB is a semicircle.
a semicircle is 180 degrees
Answer:
33.44
Step-by-step explanation:
Use this calculator to find percentages. Just type in any box and the result will be calculated automatically.
Calculator 1: Calculate the percentage of a number.
For example: 38% of 88 = 33.44
Calculator 2: Calculate a percentage based on 2 numbers.
For example: 33.44/88 = 38%
