Counter
Mathematics Dictionary
Dr. K. G. Shih

Trigonometry
Examples Link to program numbers n1 and n2


A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P |
Q | R | S | T | U | V | W | X | Y | Z |


Q01. ***A

  • Absolute operation
    • TR 27 09 y = cos(x) + sin(x) + Abs(cos(x) - sin(x))
    • TR 27 10 cos(2*x) = sin(x) + Abs(sin(x))
    • Tr 27 12 Sketch y = cos(x) - Abs(cos(x))
    • TR 27 10 cos(2*x) = sin(x) + Abs(sin(x)) : find sin(x) between 0 & 2*pi
    • TR 27 09 y = cos(x)+sin(x) + Abs(cos(x)-sin(x)) : Sketch
  • Arithmetic Progression
    • TR 07 21 sin(A) & cos(A) have AP mid terms sin(x) and GP mid term sin(y)
    • prove that 2*cos(2*x) = cos(2*y)
  • Arctangent
    • TR 08 10 Prove that 2*arctan(1/3) + arctan(1/7) = pi/4

    Go to Begin

    Q02. ***B

  • TR 27 01 Bisector of triangle AD = 2*b*c*cos(A/2)/(b + c)
    Go to Begin

    Q03. ***C

  • Cosine Law
    • TR 27 04 Equaliteral triangle ABC inscribed unit circle. P on circle.
    • Prove that PA^2 + PB^2 + PC^2 = 2*3
  • FI 02 01 Cosine law : prove that cos(A-B) = cos(A)*cos(B) - sin(A)*sin(B)
  • TR 04 10 cos(1) + cos(2) + ... + cos(179) + cos(180) = -1
  • TR 07 24 cos(20)*cos(40)*cos(60)*cos(80)
  • TR 27 10 cos(2*x) = sin(x) + Abs(sin(x)) : find sin(x) between 0 & 2*pi
  • TR 07 19 cos(A) + cos(B) + cos(C) = ? if A+B+C = pi
  • TR 07 19 cos(2*A) + cos(2*B) + cos(2*C) = ? if A+B+C = pi
  • TR 07 25 cos(pi/16)^4 +cos(3*pi/16)^4 +cos(5*pi/16)^4 +cos(7*pi/16)^4
  • TR 07 14 cos(x) + cos(3*x) + .... + cos((2*n-1)*x)
  • TR 14 10 cos(x)^6 + sin(x)^6. Find range if x between 0 and pi/2
  • TR 14 11 cos(x)^2 -4*cos(x)*sin(x) -3*cos(x)^2. Find range if x between 0 & pi/2
    Go to Begin

    Q04. ***D


    Go to Begin

    Q05. *** E
  • Equaliteral triangle ABC
    • TR 27 04 : inscribed unit circle. P on circle. prove PA^2 + PB^2 + PC^2 = 2*3
  • Equation
    • TR 09 07 Equation : x^2 - 6*x + 16*sin(A) = 0
      • 1. Find A if equation has integral roots
      • 2. Find A if equation has real roots
      • 3. Find A if equation hs complex roots
    • TR 09 08 : 1/cos(x) + 1/sin(x) = 2*Sqr(2)
    • TR 09 10 : sin(2*x)*sin(5*x) +sin(4*x)*sin(11*x) +sin(9*x)*sin(24*x) = 0
    • TR 27 10 : cos(2*x) = sin(x) + Abs(sin(x))
    • TR 27 07 : Solve simultaneous equations
      • sin(x)^3 = sin(y)
      • cos(x)^3 = cos(y)
    • TR 27 08 : Solve simultaneous equations
      • 2^(cos(x) + sin(y)) = 0
      • 16^(cos(x)^2 + sin(x)^2) = 4

    Go to Begin

    Q06. ***F


    Go to Begin

    Q07. ***G

  • TR 07 21 GP : sin(A) & cos(A) have AP mid terms sin(x) & GP mid term sin(y), ...
  • TR 07 16 GP : angles of triangle in GP and r = 2, prove that cos(A)*cos(B) + ...
  • TR 27 13 GP : Sum[((1/2)^n)*cos(n*pi/2))] for n = 1 to infinite
  • TR 27 13 GP : Sum[((1/2)^n)*cos(n*pi/2))] for n = 1 to infinite
    Go to Begin

    Q08. ***H

  • TR 27 05 Hexagon ABCDEF (regular) inscribed unit circle.
    • P on circle. Prove that PA^2 +PB^2 +PC^2 +PD^2 +PE^2 +PF^2 = 2*6

    Go to Begin

    Q09. I

  • Identity of triangle ABC
    • TR 11 01 sin(2*A) + sin(2*B) + sin(2*C) = ?
    • TR 11 02 cos(2*A) + cos(2*B) + cos(2*C) = ?
    • TR 11 03 cos(A)^2 + cos(B)^2 + cos(C)^2 = ?
    • TR 11 04 sin(A)^2 + sin(B)^2 + sin(C)^2 = ?
    • TR 11 05 sin(A) + sin(B) + sin(C) = ?
    • TR 11 06 cos(A) + cos(B) + cos(C) = ?
    • TR 11 07 cos(A/2)^2 + cos(B/2)^2 + cos(C/2)^2 = ?
    • TR 11 08 sin(A/2)^2 + sin(B/2)^2 + sin(C/2)^2 = ?
  • In-equality
    • TR 05 08 x is between 0 and 2*pi, find x if sin(x) GT cos(x)

    Go to Begin

    Q10. J


    Go to Begin

    Q11. K


    Go to Begin

    Q12. L


    Go to Begin

    Q13. M

  • TR 14 10 Max, min of cos(x)^6 + sin(x)^6. x between 0 and pi/2
  • TR 14 11 Max, min of cos(x)^2 -4*cos(x)*sin(x) -3*cos(x)^2. x between 0 & pi/2
  • TR 14 06 Max, min of (sec(A)^2 - tan(A))/(sec(A)^2 + tan(A))
  • TR 27 01 Median of triangle ABC AD = 2*b*c*cos(A/2)/(b+c)
  • TR 27 02 Medians of triangle ABC make angle x,y,z with sides
    • Angles : ADB = x, BEC = y and CFA = y
    • Prove that a*sin(2*x) + b*sin(2*y) + c*sin(2*z)
  • TR 07 23 Multiple angle : 5 + 8*cos(x) + 4*cos(2*x) + cos(3*x) GT 0
    Go to Begin

    Q14. ***N


    Go to Begin

    Q15. ***O

  • AN 11 09 Ortho-center to circum-center of triangle ABC
    • The distance : d^2 = R^2 - 8*(R^2)*cos(A)*cos(B)*cos(C)

    Go to Begin

    Q16. P

  • TR 07 11 Product of function to sum
    • Angles of triangle in 3 consecutive GP terms and common ratio = 3
    • Prove that cos(A)*cos(B) + cos(B)*cos(C) + cos(C)*cos(A) = -1/4
  • TR 07 16 Product of function to sum
    • Angles of triangle in 3 consecutive GPterms and common ratio = 2
    • Find cos(A)*cos(B) + cos(B)*cos(C) + cos(C)*cos(A) = ?
  • TR 07 00 Product functions to sum
    • TR 07 14 : S(n) = cos(x) + cos(3*x) + .... + cos((2*n-1)*x)
    • TR 07 15 : S(n) = sin(x)^2 + sin(2*x)^2 + .... + sin(n*x)^2

    Go to Begin

    Q17. Q


    Go to Begin

    Q18. R


    Go to Begin

    Q19. S

  • Series
    • TR 07 14 : S(n) = cos(x) + cos(3*x) + .... + cos((2*n-1)*x)
    • TR 07 15 : S(n) = sin(x)^2 + sin(2*x)^2 + .... + sin(n*x)^2
  • TR 07 09 sin(1) + sin(2) + ... + sin(359) + sin(360) = 0
  • TR 07 24 sin(20)*sin(40)*sin(60)*sin(80)
  • TR 07 25 sin(pi/16)^4 +sin(3*pi/16)^4 +sin(5*pi/16)^4 +sin(7*pi/16)^4
  • TR 27 05 Square ABCD inscribed unit circle.
    • P on circle. Prove that PA^2 +PB^2 +PC^2 +PD^2 = 2*4
  • Sum to product functions
    • TR 07 19 : cos(2*A) + cos(2*B) + cos(2*C) = ? if A+B+C = pi
    • TR 07 19 : sin(A)^2 + sin(B)^2 + sin(C)^2 = ? if A+B+C = pi
    • TR 07 19 : cos(A) + cos(B) + cos(C) = ? if A+B+C = pi
    • TR 07 20 : sin(A)+sin(B)=p and cos(A)+cos(B)=q, find sin(A+B)
    • TR 07 22 : If sin(x+y) = sin(x)+sin(y), find conditions
    • TR 07 22 : If x and y are acute angles, sin(x+y) LT sin(x)+sin(y)

    Go to Begin

    Q20. ***T

  • TR 27 11 (1 + tan(15))/(1 - tan(15)) = ?
  • TR 10 12 tan(A/2)*tan(B/2) + tan(B/2)*tan(C/2) + tan(C/2)*tan(A/2)
  • TR 18 03 Transformation : y = sin(x) to y - 2 = 3*Sin(2*x + pi/4)

  • Triangle ABC
    • TR 07 19 : cos(2*A) + cos(2*B) + cos(2*C) = ?
    • TR 07 19 : sin(A)^2 + sin(B)^2 + sin(C)^2 = ?
    • TR 07 19 : cos(A) + cos(B) + cos(C) = ?

    Go to Begin

    Q21. U


    Go to Begin

    Q22. V


    Go to Begin

    Q23. W


    Go to Begin

    Q24. X

  • TR 14 05 x^2 - 2*x*sin(pi*x/2) + 1 = 0 has real roots
  • TR 09 07 x^2 - 6*x + 16*sin(A) = 0 has integral roots
    Go to Begin

    Q25. Y

  • TR 27 09 y = cos(x)+sin(x) + Abs(cos(x)-sin(x)) : Sketch
  • Tr 27 12 y = cos(x) - Abs(cos(x)) : sketch
    Go to Begin

    Q26. Z


    Go to Begin

  • Show Room of MD2002 Contact Dr. Shih Math Examples Room

    Copyright © Dr. K. G. Shih, Nova Scotia, Canada.

    1