Given: △ABC, BC>AC, D∈ AC , CD=CB Prove: m∠ABD is acute
1 answer:
Answer:
Step-by-step explanation:
Given: △ABC, BC>AC, D∈ AC , CD=CB
To prove: m∠ABD is acute
Proof: In ΔABC, the angle opposite to side BC is ∠BAC and the angle opposite to side AC is ∠ABC.
Now, it is given that BC>AC, then ∠BAC>∠ABC.. (1)
In ΔBDC, using the exterior angle property,
∠ADB=∠DBC+∠BCD
∠ADB=∠DBC+∠BCA
⇒∠ADB>∠BAC (2)
From equation (1) and (2), we get
∠ADB>∠BAC
⇒∠ADB>∠ABC
⇒DB>AB
Hence, m∠ABD is acute
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Answer:
8022.
Step-by-step explanation:
Let x be the number of years after 2010.
We have been given a population of fish in a lake is 14000 in 2010. The population decreases 6% annually.
We can see that population of fish is the lake is decreasing exponentially as it is decreasing 6% annually.
Since we know that an exponential function is in form: , where,
a = Initial value,
b = For decrease or decay b is in form (1-r) where r represents decay rate in decimal form.
Let us convert our given decay rate in decimal form.
Upon substituting our given values in exponential form of function we will get the population of fish in the lake after x years as:
Let us find x by subtracting 2010 from 2019.
Upon substituting x=9 in our function we will get,
Therefore, the population of fish in 2019 will be 8022.