Solve fast ⏩⏩⏩⏩⏩⏩⏩⏩⏩
Answers
Answer:
a)3/4
B)4/5
C)37/40 please mark me the brain least answer
Question :
In the adjoining figure, ABC is an isosceles triangle in which AB = AC. Find the values of the following :
- tan θ
- sin (90° - θ)
- sec θ + cos (90° - θ)
Solution :
According to the question :
- AB = AC
- AC = 5 cm [given]
So putting it's value we get
- AB = 5 cm
So, AB is 5 cm
Now, we need to apply Pythagoras Theorem
In rt∠d ∆ADC, ∠D is 90°
(Hypotentuse)² = (Perpendicular)² + (Base)²
(AC)² = (AD)² + (CD)²
Here,
- AC = 5 cm
- CD = 3 cm
- AD = ?
Putting their respective values we get
(AD)² = (5)² - (3)²
(AD)² = 25 - 9
(AD)² = 16
AD = √16
AD = 4 cm
Now, to get the the value of base in ∆ABC using Pythagoras Theorem
In rt∠d ∆ABC, ∠D is 90°
(Hypotentuse)² = (Perpendicular)² + (Base)²
(AB)² = (AD)² + (BC)²
Here,
- AB = 5 cm
- AD = 4 cm
- BC = ?
Putting all the values we get
(5)² = (4)² + (BC)²
(BC)² = 25 - 16
(BC)² = 9
BC = √9
BC = 3
Now according to the given information we need to find :
1) tan θ
We know that,
- tan θ = perpendicular/adjacent
- tan θ = 3/4
2) sin (90° - θ)
We know that,
sin (90° - θ) = cosec θ
So formula for cos θ is
- cos θ = hypotentuse/base
- cosec θ = 5/4
3) sec θ + cos (90° - θ)
We know that,
- cos(90° - θ) = sec θ
Formula for sec θ
- sec θ = Hypotentuse/Base
- sec θ = 5/4
Now,
sec θ + sec θ
2 sec θ
2 × 5/4
5/2
Final Answers :
1) tan θ = 3/4
2) sin (90° - θ) = 5/4
3) sec θ + cos (90° - θ) = 5/2
Learn More :
Basic :
sin θ = P/H
cos θ = B/H
tan θ = P/B
cot θ = B/P
sec θ = H/B
cosec θ = H/P
Here,
P refers Perpendicular or Height
B refers Base
H refers Hypotentuse
Square Relations :
sin² θ + cos² θ = 1
sec² θ – tan² θ = 1
cosec² θ – cot² θ= 1
Quotient Relations :
sin θ× cosec θ = 1
cos θ × sec θ = 1
tan θ × cot θ = 1
Trigonometric value of standard angles :
Trigonometrical ratios of complementary angles :
sin (90° - θ) = cosec θ
cos (90° - θ) = sec θ
tan (90° - θ) = cot θ
cot (90° - θ) = tan θ
sec (90° - θ) = cos θ
cosec (90° - θ) = sin θ