1.

5 cos A=4,find the value of 1- tan^2A/sec^2 A​

Answer»

<P>Answer:

{7/25)

Step-by-step explanation:

Let ABC is a RIGHT angle ∆.

cosA = (4/5) = (B/H)

.

.

as we know that :- (PBP/HHB)

and tanA = sinA/cosA

secA = 1/cosA

and by the HELP of Phythagorean theorem

(H²) = (P²) + (B²)

(5²) = (P²) + (4²)

(P²) = (25) - (16)

(P²) = 9

√(P²) = √9 = √(3x3)

so P = 3

so other tri. ratio is :- sinA = (P/H) = (3/5)

.

.

VALUE of :-

  • 1 - tan²A/ sec²A
  • {1 - (sin²A/cos²A) } / (1/cos²A)
  • {(cos²A - sin²A) / cos²A)} / (1/cos²A)
  • now TAKING common 1/cos²A from deno. and nume.
  • so we can get

(cos²A - sin²A)

  • now put the value of cosA and sinA
  • {(4/5)² - (3/5)²}
  • {16/25 - 9/25}
  • {16 - 9}/25
  • 7/25 (ans)


Discussion

No Comment Found

Related InterviewSolutions