ట్రిగోనమెట్రీ – Step-wise Solved Problems (121–140) | Advanced Level
121. sinθ + cosθ = a అయితే sinθcosθ = ?
Step: (sinθ + cosθ)² = 1 + 2sinθcosθ
a² = 1 + 2sinθcosθ
sinθcosθ = (a² − 1)/2
Final Answer = (a² − 1)/2
122. sinθ − cosθ = a అయితే sinθcosθ = ?
Step: a² = 1 − 2sinθcosθ
sinθcosθ = (1 − a²)/2
Final Answer = (1 − a²)/2
123. sinθcosθ = a అయితే sin⁴θ + cos⁴θ = ?
Step: = 1 − 2a²
Final Answer = 1 − 2a²
124. sinθ + cosθ = a అయితే sin²θ + cos²θ = ?
Final Answer = 1
125. sinθcosθ = a అయితే (sinθ + cosθ)² = ?
Step: = 1 + 2a
Final Answer = 1 + 2a
126. tanθ = a అయితే sinθcosθ = ?
Step: sinθcosθ = tanθ / (1 + tan²θ)
Final Answer = a / (1 + a²)
127. cotθ = a అయితే sinθcosθ = ?
Step: = cotθ / (1 + cot²θ)
Final Answer = a / (1 + a²)
128. sinθ + cosθ = 1 అయితే sin³θ + cos³θ = ?
Step: = (sinθ + cosθ)³ − 3sinθcosθ(sinθ + cosθ)
= 1 − 3×0×1
Final Answer = 1
129. sinθ + cosθ = √2 అయితే sin³θ + cos³θ = ?
Step: = (√2)³ − 3×(1/2)×√2
= 2√2 − (3√2/2)
= √2/2
Final Answer = √2/2
130. sinθcosθ = 1/2 అయితే sin³θ + cos³θ = ?
Step: = (sinθ + cosθ)(1 − sinθcosθ)
= √2 × (1/2)
Final Answer = √2/2
131. sinθ + cosθ = a అయితే sin³θ + cos³θ = ?
Step: = a³ − 3a[(a²−1)/2]
Final Answer = a³ − (3a(a²−1))/2
132. sinθcosθ = a అయితే sin²θ + cos²θ = ?
Final Answer = 1
133. sinθ = cosθ అయితే sin³θ + cos³θ = ?
Step: θ = 45° → sin = cos = 1/√2
Answer = 2 × (1/√2)³ = √2/2
Final Answer = √2/2
134. sin²θcos²θ = a అయితే sin⁴θ + cos⁴θ = ?
Final Answer = 1 − 2a
135. sinθ + cosθ max value?
Final Answer = √2
136. sinθcosθ max value?
Final Answer = 1/2
137. sinθ + cosθ = 2 అయితే possible?
Final Answer = Not possible
138. sinθcosθ = 1 అయితే possible?
Final Answer = Not possible
139. tanθ + cotθ min value?
Step: ≥ 2
Final Answer = 2
140. tanθ + cotθ = 2 అయితే θ = ?
Step: tanθ = 1
Final Answer = 45°