Composition, content: what I learned in six years. Short is OK! Fast

Composition, content: what I learned in six years. Short is OK! Fast

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Calculation of trigonometric function of acute angle
sin（∠A+∠B）=?
cos（∠A+∠B）=?
tan（∠A+∠B）=?
Is there a formula for the above?
I only know sin (∠ a + ∠ b) = sin ∠ a times cos ∠ B + cos ∠ a times sin ∠ B

Sin (∠ a + ∠ b) = sin ∠ a times cos ∠ B + cos ∠ a times sin ∠ B
Cos (∠ a + ∠ b) = cos ∠ a times cos ∠ b-sin ∠ a times sin ∠ B
Tan (a + b) = (a + b) / (1-A + b)

(A-2 / a squared-1 minus 1 / A-1) △ 1 / A + 1, where a = 2cos 30 ° + Tan 45 °

a=2cos30°+tan45°.
=2*√3/2+1
=√3+1
(A-2 / a squared-1 minus 1 / A-1) △ 1 / A + 1,
=(a-2-(a+1))/(a+1)(a-1) *(a+1)
=(a-2-a-1)/(a-1)
=-3/(a-1)
=-3/(√3+1-1)
=-√3

36 degrees 54 minutes △ 6

6 degrees 9 minutes

75 degrees - 36 degrees 54 seconds = what?

75 degrees - 36 degrees 54 seconds = 74 ° 59 ′ 60 ″ - 36 ° 54 ″ = 38 ° 59 ′ 6 ″

Calculate 143 degrees 29 minutes 47 seconds + 36 degrees 30 minutes 13 seconds = how much. Fast

According to the conversion of degrees and minutes and seconds, 1 degree = 60 minutes = 3600 seconds
The answer is 180 degrees

Simple calculation: 1 / 5 * 39 + 3 / 5 * 26 + 3 / 5 * 11 =?

1/5*39+3/5*26+3/5*11
=1/5*3*13+3/5*26+3/5*11
=3/5*13+3/5*26+3/5*11
=3/5*（13+26+11）
=3/5*50
=30

2sin60 minus cot45 urgent

Root 3 minus 1,

2sin60-3tan30 + (one third) 0 power + (- 1) 2009 power

=2 * (3 under root) / 2-3 * (3 under root) / 3 + 1 + (- 1)
=3 under radical - 3 + 1 + (- 1) under radical
=0

How much is 2sin60

Root 3