Trigonometry - Chapter 9.1 (Class 9-10)
Definition
Trikonmiti holo ekti geometry er shakha jekhane tribhujer kon o bahur somporko nie alochona kora hoy.
Basic Ratios
1. sin(angle) = lomb / atibhuj
2. cos(angle) = bhumi / atibhuj
3. tan(angle) = lomb / bhumi
4. cosec(angle) = 1 / sin(angle)
5. sec(angle) = 1 / cos(angle)
6. cot(angle) = 1 / tan(angle)
Trigonometric Table
angle | sin | cos | tan
-------|------|------|------
0° | 0 | 1 | 0
30° | 1/2 | 0.87 | 0.58
45° | 0.71 | 0.71 | 1
60° | 0.87 | 1/2 | 1.73
90° | 1 | 0 | undef
Basic Formulas
1. sin^2(angle) + cos^2(angle) = 1
2. 1 + tan^2(angle) = sec^2(angle)
3. 1 + cot^2(angle) = cosec^2(angle)
Example
Q: Jodi sin A = 3/5 hoy, tobe cos A o tan A nirnoy koro.
Ans: sin A = 3/5 -> lomb = 3, atibhuj = 5 -> bhumi = sqrt(5^2 - 3^2) = 4
Definition
Trikonmiti holo ekti geometry er shakha jekhane tribhujer kon o bahur somporko nie alochona kora hoy.
Basic Ratios
1. sin(angle) = lomb / atibhuj
2. cos(angle) = bhumi / atibhuj
3. tan(angle) = lomb / bhumi
4. cosec(angle) = 1 / sin(angle)
5. sec(angle) = 1 / cos(angle)
6. cot(angle) = 1 / tan(angle)
Trigonometric Table
angle | sin | cos | tan
-------|------|------|------
0° | 0 | 1 | 0
30° | 1/2 | 0.87 | 0.58
45° | 0.71 | 0.71 | 1
60° | 0.87 | 1/2 | 1.73
90° | 1 | 0 | undef
Basic Formulas
1. sin^2(angle) + cos^2(angle) = 1
2. 1 + tan^2(angle) = sec^2(angle)
3. 1 + cot^2(angle) = cosec^2(angle)
Example
Q: Jodi sin A = 3/5 hoy, tobe cos A o tan A nirnoy koro.
Ans: sin A = 3/5 -> lomb = 3, atibhuj = 5 -> bhumi = sqrt(5^2 - 3^2) = 4
