7.If sin A -cos A = 7/13 Then is the value of sin A +cos A, where A is an acute angle is About the author Alice
Answer: 17/13 Step-by-step explanation: We know that sin²A + cos²A = 1 Now, sin A – cos A = 7/13 ⇒ (sin A – cos A)² = (7/13)² ⇒ sin²A + cos²A – 2sinAcosA = 49/169 ⇒ 1 – 2sinAcosA = 49/169 ⇒ 2sinAcosA = 1 – 49/169 = (169 – 49)/169 = 120/169 ⇒ 2sinAcosA = 120/169 ⇒ 1 + 2sinAcosA = 1 + 120/169 ⇒ sin²A + cos²A + 2sinAcosA = (169 + 120)/169 ⇒ (sin A + cos A)² = 289/169 ⇒ sin A + cos A = √(289/169) ⇒ sin A + cos A = 17/13 Hope it helps!!! Please mark Brainliest!!! Reply
Answer:
17/13
Step-by-step explanation:
We know that sin²A + cos²A = 1
Now, sin A – cos A = 7/13
⇒ (sin A – cos A)² = (7/13)²
⇒ sin²A + cos²A – 2sinAcosA = 49/169
⇒ 1 – 2sinAcosA = 49/169
⇒ 2sinAcosA = 1 – 49/169 = (169 – 49)/169 = 120/169
⇒ 2sinAcosA = 120/169
⇒ 1 + 2sinAcosA = 1 + 120/169
⇒ sin²A + cos²A + 2sinAcosA = (169 + 120)/169
⇒ (sin A + cos A)² = 289/169
⇒ sin A + cos A = √(289/169)
⇒ sin A + cos A = 17/13
Hope it helps!!! Please mark Brainliest!!!