value of tan 10°.tan 45°.tan 80° is?????
Don't spam
Answers
Answered by
2
Answer:
this question came in the final exam of class9 of icse and i was not able to do this sum sory if i could help u.......
Answered by
2
Answer:
tan10×tan15×tan75×tan80=1
Step-by-step explanation:
Given,
tan10×tan15×tan75×tan80
Rearranging the terms, we get
=(tan10tan80)×(tan15tan75)
= [tan10tan(90-10)]×[tan15tan(90-15)]
= (tan10xcot10)×(tan15cot15)
/* We know that,
i ) tan(90-A) = cotA
ii) tanAcotA = 1 */
= 1 × 1
= 1
Therefore, tan10×tan15×tan75×tan80=1
Similar questions