To prove sin1 / [Cosn ° * cos (n + 1) °] = Tan (n + 1) ° - Tan °
The key here is the communication angle: change the left 1 ° to (n + 1) ° - n ° to sin1 / [Cosn ° * cos (n + 1) °] = sin [(n + 1) ° - n °] / [Cosn ° * cos (n + 1) °] = [sin (n + 1) ° - cos (n + 1) ° Sinn °] / [Cosn ° * cos (n + 1) °] = Tan (n + 1)
RELATED INFORMATIONS
- 1. 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)]
- 2. 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) =___ .
- 3. 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
- 4. 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?
- 5. 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
- 6. Given the quadratic function, when x = 4, there is a minimum value of - 3, and the abscissa of the intersection of his image and X axis is 1, the relationship of the quadratic function is obtained
- 7. How to put the pieces of Lesson 16 in the middle of nine squares so that the sum of the pieces on each side is 7
- 8. Prove that the image of y = x + 1 / (x-1) is a centrosymmetric graph, and find its symmetry center. Find the process. Thank you
- 9. It is known that the sum of the right sides of a right triangle is equal to 8. What is the maximum area of the right triangle when the two right sides are equal to each other?
- 10. In the triangular pyramid p-abc, PA is perpendicular to the plane ABC, ∠ BAC = 60 °, PA = AB = AC = 2, and E is the midpoint of PC The cosine of the angle between AE and Pb and the volume of a-ebc are calculated
- 11. Can (COS π / 4 + isin π / 4) ^ n be expressed as (Cosn π / 4 + Sinn π / 4)? Why? Here I ^ 2 = - 1
- 12. Verification: cos α + √ 3 · sin α = 2Sin (π / 6 + α). Need detailed process, thank you
- 13. 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?
- 14. 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
- 15. 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
- 16. How is cos (x) * cos (π / 6-x) = 1 / 2 * [cos (π / 6) + cos (2x - π / 6)] derived?
- 17. The derivation of Maclaurin formula F (x) = ln (1 + x)
- 18. The McLaurin series of F (x) = x · cos (x ^ 2 / 2) is mainly used to find the n-th derivative of F (x)
- 19. McLaughlin formula of (e ^ x-1) / X expansion
- 20. Is there a similar formula for 1 / cos & # 178; X = sec & # 178; X?