2 (- cos (π / 6) + isin (π / 6)) = 2 (COS (π - π / 6) + isin (π - π / 6)) why is π - π / 6? Who can tell me

RELATED INFORMATIONS

• 1. It is proved that the nth power of (1 + cos θ + isin θ) = the nth power of 2 times the nth power of cos θ / 2 (COS n θ / 2 + isin n n θ / 2) Such as the title
• 2. The n-th root of non-zero complex R (COS θ + isin θ) is n complex numbers Is this something for Shanghai college entrance examination?
• 3. Verification: cos α + √ 3 · sin α = 2Sin (π / 6 + α). Need detailed process, thank you
• 4. Can (COS π / 4 + isin π / 4) ^ n be expressed as (Cosn π / 4 + Sinn π / 4)? Why? Here I ^ 2 = - 1
• 5. To prove sin1 / [Cosn ° * cos (n + 1) °] = Tan (n + 1) ° - Tan °
• 6. It is proved that XLN [(1 + x) / (1-x)] + cos x is greater than or equal to 1 + (x ^ 2) / 2 when (- 1 + x) / (1-x)]
• 7. Given the function f (x) = cos π X & nbsp; & nbsp; & nbsp; (x ≤ 0) f (x-1) + 1 & nbsp; & nbsp; (x > 0), then f (43) + F (- 43) =___ ．
• 8. On the derivation of half angle formula TaNx / 2 = under positive and negative root sign (1-cosx) / (1 + cosx) = (1-cosx) / SiNx Why is there no positive or negative in the last step
• 9. Please ask about proving Newton Leibniz formula Proof: let the upper limit be a variable, define a new function g [x], prove G '(x) = f (x), and then say g (x) C = f (x), but doesn't g (x) = f (x) C also hold?
• 10. Points E and F are the midpoint of AD and DC on square ABCD, respectively. Be and CF intersect at point P, and AP = AB is proved It requires a vector solution
• 11. How is cos (x) * cos (π / 6-x) = 1 / 2 * [cos (π / 6) + cos (2x - π / 6)] derived?
• 12. The derivation of Maclaurin formula F (x) = ln (1 + x)
• 13. The McLaurin series of F (x) = x · cos (x ^ 2 / 2) is mainly used to find the n-th derivative of F (x)
• 14. McLaughlin formula of (e ^ x-1) / X expansion
• 15. Is there a similar formula for 1 / cos & # 178; X = sec & # 178; X?
• 16. The formula Sin & # 178; π / 2 = cos & # 178; π / 2=
• 17. What are the formulas of Sin & # 178; α = (1-cos (2 α)) / 2 and Sin & # 178; α = (1-sin (2 α)) / 2
• 18. Sin & # 178; X =? Cos & # 178; =? Theorem formula
• 19. If cos (x + π 4) = 45, X ∈ (− π 4, 0), then SiNx=______ ．
• 20. When x →∞, limx / SiNx = ∞